I do LOVE lighthouses! I got a chance to see four more on this trek - Currituck, Bodie, Cape Hatteras, and Roanoke Marsh Light. The spiral staircase was from the insides of Currituck. Quite a few of you thought a lighthouse - Phil, Michelle, Carol, Peyton, Milt, Ted, and Michael K. while another good guess was a spiral staircase (Tony and Pete) and good effort from Deana, EMO, and Joani. Here is the outside of it:
This architectural structure houses a museum for what? Look carefully at it. . .