The Mark Twain Building's upper 6 floors each have identical layouts, with 17 unique apartments. Apartment numbers are indicated by the floor number, followed by the unit number. For example, apartments 814, 614, and 314 have the same layout, but are located on the 8th,6th, and 3rd floors, respectively.
Browse the 17 unique layouts here, and take note of which apartment may be right for you! Each gallery also contains the layout of the apartment, and the images can be enlarged by clicking on them.
Available apartments can be found here.