Some say this building is Frank Lloyd Wright's simplest, most beautiful work standing.. In Short Originally intended as an upscale gift store, the building that now houses Folk Arts International and Xanadu Tribal Arts was designed in 1948. From the inconspicuous brick exterior, a Romanesque arch leads to an atrium-lined tunnel that takes you inside. The luminous interior incorporates the now legendary spiral ramp theme, which Wright also used for the Guggenheim Museum. This incontestably classy structure is located in what was once the Barbary Coast's most infamous red-light district. Climb to the top of the spiral ramp and enjoy the vertiginous beauty of the building's stunning interior.