As of 2003, the city has an estimated population of 188,660, making it the largest city in the Kyoto prefecture apart from Kyoto itself and the density of 2,792.89 persons per km². The total area is 67.55 km². The city sits on the Uji River ("Ujigawa"), which has its source in Lake Biwa ("Biwa-ko"). In the 4th century the son of Emperor Ojin established a palace in Uji.
Uji is famous in Japan for a number of reasons:
- it is the home of Byoodoin (also known as Amida Hall or Phoenix Hall), the world's oldest wooden structure, built in 1053, a UNESCO World Heritage Site;
- it is the site of the Battle of Ujigawa;
- it boasts an abundance of Shinto and Buddhist temples, all clustered about the centre of the town, including the Kosho-ji Zen temple, constructed in 1648, with its famous Kotozawa slope entrance (framed with dense thickets of peach, plum, willow, cherry, and maple trees, each of which dramatically change colour with the seasons). It also is home to Ujigami Jinja Shrine, another UNESCO World Heritage Site;
- it is the source of "Uji Tea", a form of very high quality Japanese tea. Shogun Yoshimitsu Ashikaga (1358-1408) promoted cultivation of green tea in the Uji area, and since that time Uji has been an important production and distribution centre of superior quality green tea (including Tsuen tea, continuously manufactured since 1160).