Question: Mark Masons' Hall in London is on the opposite of which palace??

Context paragraphs:
Murray General Merchandise Store: The Murray General Merchandise Store, also known as Murray Hall, is a historic building located in Little Sioux, Iowa, United States.  A native Scot, Michael Murray operated a general store from this location from 1877, when it was built, to 1916 when he died.  The second floor housed the local chapters of the Masons, Independent Order of Odd Fellows, Order of the Eastern Star, Grand Army of the Republic, and the Woodmen.  By the 1970s the Masons and the Eastern Star were the only two remaining, but they folded in the 1980s.  The Harrison County Historic Preservation Commission took possession of the building in the 1990s to preserve it.  Since then it has served a community social hall, and served as city hall briefly in 1996 when the old city hall was destroyed in a fire.

History of Freemasonry: The history of Freemasonry encompasses the origins, evolution and defining events of the known as Freemasonry.  It covers three phases.  Firstly, the emergence of organised lodges of operative masons during the Middle Ages, then the admission of lay members as "accepted" or speculative masons, and finally the evolution of purely speculative lodges, and the emergence of Grand Lodges to govern them.  The watershed in this process is generally taken to be the formation of the first Grand Lodge in London in 1717.  The two difficulties facing historians are the paucity of written material, even down to the 19th century, and the misinformation generated by masons and non-masons alike from the earliest years.

Order of Knight Masons: The Order of Knight Masons is a secular, chivalric Masonic order, open to all Master Masons who are also members of a Mark Lodge and a Royal Arch Chapter.  Members of the order meet in Councils of Knight Masons which are governed by the Grand Council of Knight Masons based in Dublin, Ireland.  A member of the group is a Knight Mason.

St James's Palace: St James's Palace is the most senior royal palace in the United Kingdom.  Located in the City of Westminster, although no longer the principal residence of the monarch, it is the ceremonial meeting place of the Accession Council and the London residence of several members of the royal family.

National Grand Lodge: The Most Worshipful National Grand Lodge Free & Accepted Ancient York Masons Prince Hall Origin National Compact USA (also referred to as Prince Hall Origin as well as Compact Masons) is a body of Prince Hall Freemasonry in the United States of America composed predominantly of African American Freemasons.

Mark Masons' Hall, London: Mark Masons' Hall in London is the headquarters of The Grand Lodge of Mark Master Masons of England and Wales, which also controls the Royal Ark Mariner degree.  It is located in 86 St James's Street in the central London district of St James's, opposite St James's Palace.  While Freemasons' Hall is the headquarters of the United Grand Lodge of England and the Supreme Grand Chapter of Royal Arch Masons of England, Mark Masons' Hall is the home of several other important appendant orders of Freemasonry in England and Wales.

Adams Vacuum &amp; Sewing building: The Adams Vacuum & Sewing building (also known as the Montrose Masonic Temple) refers to a historic building in Montrose, Colorado.  Constructed in 1911 as a meeting hall for Montrose Lodge No. 63, Ancient Free and Accepted Masons, the building is in the Classical Revival style.  The Masons met in the upper floors, while the ground floor was rented out as commercial space (in addition to the Adams Vacuum and Sewing company, it has held a printing and office supply store and a funeral home).  The lodge no longer meets in the building.  The building was listed on the National Register of Historic Places in 2004.

Larmenius Charter: The Larmenius Charter or "Carta Transmissionis" ("Charter of Transmission") is a manuscript purportedly created by Johannes Marcus Larmenius (Fr.: Jean-Marc Larmenius) in February 1324, giving in Latin a list of 22 successive Grand Masters of the Knights Templar after Jacques de Molay, ending in 1804, the name of Bernard-Raymond Fabré-Palaprat appearing last on the list (who revealed the existence of the Charter in 1804).  The document is written in a supposed devised ancient Knights Templar Codex.  Actually in Freemason custody, the document is kept at the Mark Masons Hall in London.  Based on analysis of the deciphered code as well as of the circumstances of the finding of the charter, most researchers have concluded that it is a forgery.

Vermont Masonic Hall: The Vermont Masonic Hall, also known as the Vermont Hardware Store Building, is a historic Masonic Lodge located on North Main Street in Vermont, Illinois.  The hall was built in 1891-92 for Vermont's Lodge No. 116 of Ancient, Free and Accepted Masons, which was formed in 1852.  At the time the hall was built, secret societies were enjoying a wave of popularity in America, with the Masons preeminent among them; Vermont was no exception to this trend, and its Masons played an important role in the city's social life.  The hall was a two-story commercial building; the Masons leased the second floor, while a hardware store operated on the first.  The brick building features an elaborate iron storefront; its design, along with the lodge itself, led it to be considered of the best Masonic lodges in western Illinois.

Grand Lodge of California: The Grand Lodge of Free & Accepted Masons of California, commonly called the Grand Lodge of California, is one of two Masonic Grand Lodges in the state recognized by the United Grand Lodge of England (the other being the Most Worshipful Prince Hall Grand Lodge of California Free & Accepted Masons).  The Grand Lodge of California is headquartered in San Francisco, California.

Supporting paragraphs: Mark Masons' Hall, London St James's Palace
Answer: St James's Palace