Sanzen-in temple is located in Ohara district of Sakyo ward of Kyoto city. Ohara is famous for shiso mint field.
The temple was originally built in 8th century by Saicho, who built the Enryakuji temple on Mt.Hiei. Then, moved several times and finally moved to Ohara in 1871. Churches in Europe can be rebuilt by usually stand on the same places but Japanese temples are normal to move its location, especially in Kyoto. This is due to civil war or decision of the rulers of Japan.
Sanzen-in is quite far located from downtown Kyoto. It takes 60 minutes by bus from Kyoto station or 22 minutes from Kokusaikaikan metro station. Just watch out that one day bus card cannot be used to Ohara. Then, there are not so many places to eat around Sanzen-in. Better to visit early in the morning or after lunch.