From the World Heritage inscription:
Nara was the capital of Japan from 710 to 784. During this period the framework of national government was consolidated and Nara enjoyed great prosperity, emerging as the fountainhead of Japanese culture. The city’s historic monuments – Buddhist temples, Shinto shrines and the excavated remains of the great Imperial Palace – provide a vivid picture of life in the Japanese capital in the 8th century, a period of profound political and cultural change.
While in Kyoto, a must day trip is a visit to Nara. In many respects, Nara can be thought of as the sister city to Kyoto. It was the capital of Japan before it was moved to Kyoto and also contains many historic shrines and temples.
The primary building in Nara is the Todaiji Temple (shown above) which is thought to be the largest wooden building in the world. The temple is home to the largest Buddha statue in Japan: The Daibutsu. The current building was finished in 1709 and replaced an even larger structure which was destroyed by fire.
One of the unique features of the city are the small red deer which roam around freely. If you go to the central park in the city, you can buy small packets of crackers to feed the deer, which are quite tame.
View my complete list of UNESCO World Heritage sites.