Located at 42nd Street and Madison Avenue in New York City, it had been built in 1949 by the Leland Baxter Paper Company. Originally designed as a high-rise industrial site to accommodate pulp recycling machinery to serve the mid-Manhattan area, each floor height is 24 feet (7.3 m). The top 5 floors of the 35-story building were purchased outright by the Fantastic Four.

         The building's steel frame construction utilized the first application of "K bracing" in the world and is one of the strongest structures of its kind. The Baxter Building is located a few city blocks from the United Nations Building. Reed Richards has applied for many land-use zone variations to allow massive reconstruction of the top five floors for the installation of a heavily-silenced silo, with a muffled rocket.

         The design of the headquarters of the Fantastic Four is along strictly utilitarian lines, except for apartments and public areas. All aspects of the design are constantly being improved, including security. For example, windows are 2 ft (0.61 m) thick composites of various glasses and plastics which are mirrored on the outside. Solid, armored, exterior walls are also mirror-clad and are indistinguishable from transparent sections.
The top five sections of the Baxter Building are completely airtight; all doors are airlocks. Complete environmental support (including atmosphere) is provided by the area between elevators 2, 3, and 4 on all floors. The building's steel-alloy framework is rigid enough to be stood on one corner and not collapse. 

         The buffer-zone is the interface between the top five floors and the lower levels. It provides a rapid-disconnect between upper and lower segments of building. It contains an array of large oil-rams to dampen any oscillations between the five upper levels and the base of the building. The buffer-zone contains some support equipment for the upper levels, but mostly it is the "mechanical floor," which provides heating, ventilation, air-conditioning and elevator support equipment for the lower 30 stories.