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                                                                  Exhibit 10.1

                      AMENDMENT TO STOCK PURCHASE AGREEMENT

         THIS AMENDMENT TO STOCK PURCHASE AGREEMENT (this "AMENDMENT") is made
and entered into as of November 5, 2001, among SENIOR HOUSING PROPERTIES TRUST
("SNH"), a Maryland real estate investment trust, SNH/CSL PROPERTIES TRUST
("ACQ. SUB"), a Maryland real estate investment trust, CRESTLINE CAPITAL
CORPORATION ("CLJ"), a Maryland corporation, and CSL GROUP, INC. ("CSL"), an
Indiana corporation.

                                    RECITALS:

         SNH, ACQ. SUB, CLJ and CSL have entered into a Stock Purchase Agreement
dated as of August 9, 2001 (the "STOCK PURCHASE AGREEMENT"), and have agreed,
subject to the terms and conditions set forth below, to amend the Stock Purchase
Agreement as provided below.

         NOW THEREFORE, In consideration of the foregoing, and the
representations, warranties, covenants and agreements set forth in this
Amendment, the parties agree as follows:

         Section 1. DEFINITIONS. Except as otherwise defined in this Amendment,
capitalized terms used herein shall have the meanings ascribed thereto in the
Stock Purchase Agreement.

         Section 2. AMENDMENTS. Effective as of the date hereof, the Stock
Purchase Agreement shall be amended as follows:

         (a)  Clause (ii) to the second recital paragraph is amended in full to
              read as follows:

              (ii) to lease all of the Communities to an entity to be designated
              by SNH ("TENANT"), each of which Communities shall be further
              subleased to a Subsidiary of Tenant (each, a "SUBTENANT").

         (b)  Section 1.1(35) of the Stock Purchase Agreement is deleted in its
entirety, and a new Section 1.1(55A) is added to the Stock Purchase Agreement to
read as follows:

                   (55A) "Life Care Amounts": any amounts paid to any of the
              Acquired Companies, MSLS or any former owner or operator of the
              Communities for so-called "continuing care contracts" (regardless
              of the Person to which they were paid and whether or not
              refundable).

         (c)  Section 1.1(54) of the Stock Purchase Agreement is amended in full
to read as follows:

                   (54) "Lease": collectively, the master lease agreement to be
              entered into on or prior to the Closing Date by and between each
              Acquired Company which owns the Communities and Tenant, and any
              sublease to be entered into on or prior to the Closing Date
              between Tenant and any Subtenant, such master lease


<PAGE>

              agreement or sublease to be in form and substance satisfactory to
              SNH and ACQ. SUB on the one hand, and Tenant or such Subtenant on
              the other.

         (d)  Section 2.3(a)(a)(B) is amended by replacing the amount
"$4,707,092" with the amount "$5,057,092".

         (e)  Section 2.3(a)(a)(D) is amended in full to read as follows:

              (D) an amount equal to the Life Care Amounts reflected as
              liabilities of the Acquired Companies pursuant to GAAP as of the
              Closing Date

         (f)  Section 3.19 of the Stock Purchase Agreement is amended by adding
a new paragraph (i) thereto to read as follows:

                   (i) CCC Leisure Park Corporation, a Delaware corporation
              ("CCC LEISURE PARK"), was incorporated on September 24, 1993; CCC
              Boynton was incorporated on April 17, 1995; and CCC Senior Living
              was incorporated on April 12, 2000. Each of CCC Leisure Park, CCC
              Boynton and CCC Senior Living has at all times since the date of
              its incorporation been a wholly-owned subsidiary in one or more
              affiliated groups of corporations filing consolidated Tax Returns
              pursuant to Sections 1501-1504 of the Code and related Treasury
              Regulations thereunder; none of such corporations has ever,
              pursuant to Section 381 of the Code, succeeded to the earnings and
              profits of another corporation through merger, liquidation or
              otherwise.

         (g)  The second paragraph of Section 5.4 of the Stock Purchase
Agreement is amended in full to read as follows:

                   By a letter dated October 23, 2001 from David Hegarty, the
              President of SNH to Tracy M. J. Colden, Esq., Senior Vice
              President, General Counsel and Corporate Secretary of CLJ, SNH has
              notified CLJ of certain environmental and other issues involving
              certain of the Properties that SNH has requested be remedied. CLJ
              shall, on or prior to November 16, 2001, notify SNH whether CLJ
              elects to take such action as may be required to cause such issues
              to be remedied. If CLJ elects to remedy the issues objected to by
              SNH, such issues shall be remedied at or prior to Closing, or, if
              any such issue cannot be completed by Closing, CLJ shall promptly
              begin such remediation and diligently pursue completion through
              and, if necessary, after Closing. If CLJ elects not to remedy any
              such issue, SNH shall, within five Business Days of its receipt of
              notice of CLJ's election not to remedy such issue, elect whether
              to terminate this Agreement.

         (h)  Section 5.6 of the Stock Purchase Agreement is amended by deleting
the words "On of before" beginning the first sentence of Section 5.6, and
substituting in lieu thereof the word "Before".


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         (i)  Section 5.7 of the Stock Purchase Agreement is amended by adding a
new paragraph (h) thereto to read as follows:

                  (h) CSL shall take the following actions prior to the Closing
                      Date:

                        (i) CSL will organize FS Tenant Holding Company Trust, a
                   Maryland business trust ("CSL TENANT HOLDING COMPANY"), as
                   its wholly owned, bankruptcy remote Subsidiary, and will
                   cause CSL Tenant Holding Company to organize FS Tenant Pool
                   II Trust and FS Leisure Park Tenant Trust, each a Maryland
                   business trust (the "NEW LOAN SUBTENANT" and the "LEISURE
                   PARK SUBTENANT," respectively), as wholly owned, bankruptcy
                   remote Subsidiaries of CSL Tenant Holding Company;

                        (ii) CSL shall form the borrowers under the New Loan as
                   Maryland business trusts (the "NEW LOAN BORROWERS") (each of
                   which shall be a direct or indirect Subsidiary of CSL) and
                   cause the New Loan Borrowers and Leisure Park Venture Limited
                   Partnership to enter into a master lease agreement with CSL
                   Tenant Holding Company (the "CSL TENANT MASTER LEASE") in
                   substantially the form furnished to CSL by SNH (and approved
                   by CSL), pursuant to which the New Loan Borrowers and Leisure
                   Park Venture Limited Partnership will lease the Properties
                   owned by them to CSL Tenant Holding Company; and

                        (iii) CSL shall cause CSL Tenant Holding Company to
                   enter into sublease agreements with each of FS Tenant Pool II
                   Trust and FS Leisure Park Tenant Trust (the "SUBLEASES") in
                   substantially the form furnished to CSL by SNH (and approved
                   by CSL) pursuant to which CSL Tenant Holding Company will
                   sublease the Properties owned by the New Loan Borrowers to FS
                   Tenant Pool II Trust and the Property owned by Leisure Park
                   Venture Limited Partnership to FS Leisure Park Tenant Trust.

         (j)  Section 5 of the Stock Purchase Agreement is further amended by
adding a new Section 5.14 thereto to read as follows:

                   5.14. CHANGE OF NAME.

                   SNH agrees that it will cause the name of any Acquired
              Company to be changed promptly after the Closing Date to the
              extent necessary to eliminate use of the word "Crestline" in such
              name.

         (k)  Section 6.1(g) of the Stock Purchase Agreement is amended by
deleting the word "Tenant" in the two places where it appears, and substituting
in lieu thereof the words, "Tenant or Subtenant, as the case may be".

         (l)  Section 6.3(a) of the Stock Purchase Agreement is amended by
deleting the period at the end thereof and substituting in lieu thereof the
following:


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<PAGE>

              , provided further, however, that none of CLJ, CSL or any of their
              Subsidiaries shall be in violation of any representation or
              warranty set forth in this Agreement for actions taken by any of
              them in accordance with SECTION 5.7(H).

         (m)  Section 7.3(a) of the Stock Purchase Agreement is amended in full
to read as follows:

                   (a) Subject to SECTION 7.1, SNH shall defend, indemnify and
              hold harmless CLJ, its Affiliates and their respective, officers,
              directors, employees and agents (the "CLJ Indemnitee"), against
              and in respect of any Losses resulting from: (i) any breach by SNH
              of any of its representations or warranties contained in this
              Agreement; (ii) any breach by SNH of any of its covenants,
              agreements or obligations contained in this Agreement; (iii) the
              lease of the Property owned by Leisure Park Venture Limited
              Partnership that is contemplated by SUBPARAGRAPHS (II) and (III)
              to SECTION 5.7(H) hereof, to the extent arising under the Loan
              Agreement referenced in SECTION 1.1(90) to the Disclosure
              Schedule; and (iv) any and all actions, suits, proceedings,
              claims, demands, assessments and judgments incident to any of the
              foregoing.

         (n)  Section 9.6 of the Stock Purchase Agreement is amended by deleting
the word "and" before "(v)" in the fourteenth line and adding a new subsection
(vi) thereto to read as follows:

              and (vi) all fees and costs, including reasonable legal fees,
              incurred in connection with forming the new tenant and subtenant
              entities and entering into the CSL Tenant Master Lease and
              Subleases.

         (o)  Section 3.3 to the Disclosure Schedule (which is incorporated by
reference in Section 1.1(27) to the Disclosure Schedule) is hereby amended by
adding the following at the end thereof:

<TABLE>
<CAPTION>

SUBSIDIARY/          TYPE OF ENTITY  JURISDICTION  CAPITALIZATION  RECORD HOLDERS
AFFILIATE                            OF FORMATION
<S>                  <C>             <C>           <C>             <C>
FS Tenant Holding    business trust  Maryland      1000 common     CSL Group, Inc.
Company Trust

FS Tenant Pool II    business trust  Maryland      1000 common     FS Tenant Holding
Trust                                                              Company Trust

</TABLE>

         (p)  Section 3.3 to the Disclosure Schedule (which is incorporated by
reference in Section 1.1(27) to the Disclosure Schedule) is hereby further
amended to add each New Loan Borrower and the Leisure Park Subtenant (as such
terms are defined in Sections 5.7(h) of the Stock Purchase Agreement, as amended
hereby) thereto effective upon its formation pursuant to 5.7(h)(i) or (ii) of
the Stock Purchase Agreement as amended hereby (each of such entities being
reflected as a Maryland business trust with 1000 shares of common stock issued
and outstanding, all of which are owned of record by CSL or a wholly-owned
Subsidiary thereof).


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<PAGE>

         (q)  Section 5.6 to the Disclosure Schedule is hereby amended by
deleting the references to CCC Leisure Park Corporation and CCC Boynton Beach,
Inc. (items 9 and 10 to such Schedule) from such Schedule.

         Section 3.  MISCELLANEOUS

         (a)  Except as herein provided, the Stock Purchase Agreement shall
remain unchanged and in full force and effect, and is hereby ratified and
confirmed.

         (b)  This Amendment is to be construed and enforced in accordance
with, and the rights of the parties shall be governed by, the law of the
State of Maryland (without giving effect to any laws or rules relating to
conflicts of laws that would cause the application of the laws of any
jurisdiction other than the State of Maryland).

         (c)  This Amendment may be executed in two or more counterparts,
each of which shall be deemed an original and all of which shall together be
considered one and the same agreement, and it shall not be necessary in
making proof of this Amendment or the terms of this Amendment to produce or
account for more than one of such counterparts.

         (d)  The Declaration of Trust of SNH, a copy of which is duly filed
with the Department of Assessments and Taxation of the State of Maryland,
provides that the name "Senior Housing Properties Trust" refers to the
trustees under such Declaration of Trust collectively as trustees, but not
individually or personally, and that no trustee, officer, shareholder,
employee or agent of SNH shall be held to any personal liability, jointly or
severally, for any obligation of, or claim against, SNH. All persons dealing
with SNH in any way shall look only to the assets of SNH for the payment of
any sum or the performance of any obligation.

         (e)  The Declaration of Trust of ACQ. SUB, a copy of which is duly
filed with the Department of Assessments and Taxation of the State of
Maryland, provides that the name "SNH/CSL Properties Trust" refers to the
trustees under such Declaration of Trust collectively as trustees, but not
individually or personally, and that no trustee, officer, shareholder,
employee or agent of ACQ. SUB shall be held to any personal liability,
jointly or severally, for any obligation of, or claim against, ACQ. SUB. All
persons dealing with ACQ. SUB in any way shall look only to the assets of
ACQ. SUB for the payment of any sum or the performance of any obligation.

         (f)  No director, officer, shareholder, employee or agent of CLJ shall
be held to any personal liability, jointly or severally, for any obligation of,
or claim against, CLJ or its Subsidiaries hereunder. All persons dealing with
CLJ in any way shall look only to the assets of CLJ for the payment of any sum
or the performance of any obligation.

         [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]


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         EXECUTED under seal as of the date first above written.

                                            SENIOR HOUSING PROPERTIES TRUST


                                            By: /s/ DAVID J. HEGARTY
                                                ------------------------------
                                            Name:  David J. Hegarty
                                            Title: President


                                           SNH/CSL PROPERTIES TRUST


                                            By:/s/ DAVID J. HEGARTY
                                               -------------------------------
                                            Name:  David J. Hegarty
                                            Title: President


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<PAGE>

                                            CSL GROUP, INC.


                                            By: /s/ LARRY K. HARVEY
                                                ------------------------------
                                            Name:  Larry K. Harvey
                                            Title: Vice President


                                           CRESTLINE CAPITAL CORPORATION


                                            By: /s/ LARRY K. HARVEY
                                                ------------------------------
                                            Name:  Larry K. Harvey
                                            Title: Senior Vice President


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