Staircases on the first floor of the Centre Family Dwelling in Shaker Village
of Pleasant Hill, Ky., form parallel lines, typical of Shaker architecture. The
double staircases are common features in Shaker architecture, because each
house was divided so that men and women did everything separately - using
different staircases, different doors and sitting on opposite sides of the room.
This structure was built in the early 1800s. Many structures in the village, a
National Historic Landmark, have been restored and are used as an inn for lodging.
Additional images from Shaker Village are in my Shaker Village gallery.

The official website for Shaker Village is http://www.shakervillageky.org .
A good history of the site is on Wikipedia: http://en.wikipedia.org/wiki/Pleasant_Hill,_Kentucky .