Kiyomizu-dera (清水寺） or "Kiyomizu Temple" is located on the side of the Higashiyama Mountains in eastern Kyoto City. Kiyomizudera is a very famous temple, not only in Kyoto city but throughout Japan. This temple is known for it's large hanging platform from a mountain edge.
Hence the expression "take the plunge at Kiyomizudera" that this temple is famously known for. It does not mean that people should be jumping off the temple's platform but it urges people to follow their dreams and goals.
This temple is close to the city center and is very popular with tourists both foreign and Japanese.