Question: What type of structure does 277 Park Avenue and 126 Madison Avenue have in common?

Context:
Squadron A Armory
The Squadron A Armory is a former United States Army armory and the homebase of Squadron A.
 It took up the whole block between Madison Avenue and Park Avenue, between 94th and 95th Street.
 It was therefore also known as the Madison Avenue Armory.
 A surviving part of the building is listed on the National Register of Historic Places as Madison Avenue Facade of the Squadron A Armory and is a New York City landmark.
126 Madison Avenue
126 Madison Avenue (also known as 15 East 30th Street) is a proposed residential skyscraper under development by Fosun Property in NoMad, Manhattan, New York City.
 The building will rise 47 stories or 730 feet, and is expected to be completed by 2018.
 J.D. Carisle Development Corp. is co-developing the project with Fosun Group, and Handel Architects is designing.
 The developers are planned to begin construction in the second half of 2015.
55 Water Street
55 Water Street is a 687 ft skyscraper in the Financial District of Lower Manhattan, New York City, on the East River.
 The 53-story, 3.5 e6sqft structure was completed in 1972.
 Emery Roth & Sons designed the building, which is tied with 277 Park Avenue as the 40th-tallest building in New York City.
 When it was completed it was the largest office building in the world, and is still the largest in New York by floor area.
 In an arrangement with the Office of Lower Manhattan Development, it was built on a superblock created from four adjoining city blocks, suppressing the western part of Front Street.
Calvary Church (Manhattan)
Calvary Church is an Episcopal church located at 277 Park Avenue South on the corner of East 21st Street in the Gramercy Park neighborhood of Manhattan, New York City, on the border of the Flatiron District.
 It was designed by James Renwick, Jr., the architect who designed St. Patrick's Cathedral and Grace Church, and was completed in 1848.
 The church complex is located within the Gramercy Park Historic District and Extension.
 It is one of the two sanctuaries of the Calvary-St.
 George's Parish.
Metropolitan Life Insurance Company Tower
The Metropolitan Life Insurance Company Tower, colloquially known as the Met Life Tower, is a landmark skyscraper located on Madison Avenue near the intersection with East 23rd Street, across from Madison Square Park in Manhattan, New York City.
 Designed by the architectural firm of Napoleon LeBrun & Sons and built by the Hedden Construction Company, the tower is modeled after the Campanile in Venice, Italy.
 The hotel located in the clock tower portion of the building has the address 5 Madison Avenue, while the office building covering the rest of the block, occupied primarily by Credit Suisse, is referred to as 1 Madison Avenue.
Church of St. Ignatius Loyola (New York City)
The Church of St. Ignatius of Loyola is a Roman Catholic parish church located on the Upper East Side of Manhattan, New York City, administered by the Society of Jesus (Jesuits).
 The parish is under the authority of the Archdiocese of New York, and was established in 1851 as St. Lawrence O'Toole's Church.
 In 1898, permission to change the patron saint of the parish from St. Lawrence O’Toole to St. Ignatius of Loyola was granted by Rome.
 The address is 980 Park Avenue, New York City, New York 10028.
 The church on the southwest corner of Park Avenue and 84th Street is part of a Jesuit complex on the block that includes Wallace Hall, the parish hall, beneath the church, the rectory at the midblock location on Park Avenue, the grade school of St. Ignatius's School on the north midblock location of 84th Street behind the church and the high school of Loyola School (also 980 Park Avenue) at the northwest corner of Park Avenue and 83rd Street.
 In addition, another Jesuit high school, Regis High School (55 E 84th Street), occupies the midblock location on the north side of 84th Street.
 The church was added to the National Register of Historic Places on July 24, 1980.
Park Avenue
Park Avenue is a wide New York City boulevard which carries north and southbound traffic in the borough of Manhattan.
 For most of the road's length in Manhattan, it runs parallel to Madison Avenue to the west and Lexington Avenue to the east.
 Park Avenue's entire length was formerly called Fourth Avenue; the title still applies to the section between the Bowery and 14th Street.
 Meanwhile, the section between 14th and 17th Street is called Union Square East, and between 17th and 32nd Streets, the name Park Avenue South is used.
277 Park Avenue
277 Park Avenue is an office building in the Midtown Manhattan neighborhood of New York City.
 It stands on the east side of Park Avenue between East 47th and 48th Streets; it is 687 ft tall, with 50 floors.
383 Madison Avenue
383 Madison Avenue is an office building owned and occupied by JP Morgan Chase in New York City on a full block bound by Madison Avenue and Vanderbilt Avenue between East 46th and 47th Streets.
 Formerly known as the Bear Stearns Building, it housed the world headquarters of the now-defunct Bear Stearns from the building's completion until Bear's collapse and sale to JPMorgan Chase in 2008.
 The building now houses the New York offices for J.P. Morgan's investment banking division, which formerly occupied 277 Park Avenue.
 Both 383 Madison and 277 Park are adjacent to JPMorgan Chase's world headquarters at 270 Park Avenue.
Metropolitan Life North Building
The Metropolitan Life North Building, now known as Eleven Madison, is a 30-story art deco skyscraper on Madison Square Park in Manhattan, New York City, at 11-25 Madison Avenue.
 The building is bordered by East 24th Street, Madison Avenue, East 25th Street and Park Avenue South, and is connected by an elevated walkway to the Met Life Tower just south of it.
 The North Building was built on the site of Richard Upjohn's original Madison Square Presbyterian Church.
 The second church, designed by Stanford White of McKim, Mead and White was built in 1906, across 24th street on land conveyed by Metropolitan Life.
 As part of the Metropolitan Life Home Office Complex, the North Building was added to the National Register of Historic Places on January 19, 1996.

Answer: building