Kencho-ji enlightenment gate

The main gate of a Zen temple is called sangedatsumon, meaning "enlightenment gate", or more simple sanmon. The size of the gate depend on the rank of the temple, so the lower rank temples have a single-storied gate, while the higher rank temples have a 2-storied gate, further differentiated by width and by the number of bays.

Photographed here is the gate of the Kencho-ji temple in Kamakura, a medium rank temples with a lx2-bay gate.