The oldest temple in Tokyo. The Asakusa area is also old and interesting, and where many low-rent hostels are located. Some nice shopping streets, old cafes, and an ancient amusement park I wouldn't risk trying.
Enryakuji Temple is a Buddhist temple, which was established in 788 on Mt Hiei, where it looks over Kyoto. Enryakuji Temple expanded over the years to become a large temple complex and is a UNESCO World Heritage Site.