I have always been interested in Patterns. Bricks, stones, buildings, bicycles, spires, bridges. . .just about anything can be fair game.

Museum Stairs and Ceiling
Phantom Drinking Fountain
Technicolor Leaves
Tree Limbs and Moon
Logs in Water
The Seattle Great Wheel
Old Bridge and Modern Boats
Bodega Window
Helicoid: An object of spiral or helical shape; a surface formed by simultaneously moving a straight line along an axis and rotating it around it (like a screw thread). 
Triple Bridge
Down, Down, Down
Scrolling SS
French Bridge
Stone Wall
Swirling Dome