A Torii ( 鳥居） is a traditional Japanese gate commonly found in Shinto Shrine. It has two upright support and two crossbars on top and is frequently painted vermilion. Torii marked the entrance to a sacred place in Japan. Here are some famous torii :
Fushimi Inari Taishi Kyoto
If you remember watching Sayuri/Memoir of the Geisha , this is the place.
The torii of Itsukushima Shrine or famously known as Miyajima. If you can see people carrying blue plastic shopping ba, that is us at the base of the torii.
(Photo Courtesy of Ruban)
One of the largest Torii in Japan @ Heian Shrine in Kyoto
These are just some of the gates you can fin as you go temple hopping in Japan.