Called Temizuya, these are open pavilions, with a running water basin inside, as you can see in this photo taken at Tsurugaoka Hachimangu, in Kamakura. Little architectural jewels, these constructions are often beautifully decorated with themes similar to the main building of the shrine.
EXIF info:
Nikon D300
Lens: 18-70mm F/3.5-4.5G
Focal Length: 31mm
Aperture: F/4.5
Shutter Speed: 1/160s
ISO Sensitivity: ISO 200