Torii is the gate in front of shrines on the border through which you enter the sacred area. Typically painted vermilion, often it is also made of stone or wood, unpainted.
Tory means bird (tori) abode. I loved a wooden gate I saw with some birds perched on top in Yoshinogari, the archeological site in Kyushu.
There are some must-see shrines with impressive gates such as the huge gate in the sea of Itsukushima Shrine (Hiroshima and Another Island) and Fushimi Taisha with hundreds gates through which you walk all the way to the top of the hill. Torre are everywhere in japan if you pay attention. I took some photos of small gates tucked away between buildings in my hometown.
I dare not have a bright vermillion gate on my garden, but a small wooden one with some birds on top would be nice.