Nara's star attraction is its Daibutsu (Great Buddha), one of the largest bronze statues in the world. It was unveiled in 752, upon the completion of the Daibutsu-den (大仏殿, Great Buddha Hall), built to house it. Both have been damaged over the years; the present statue was recast in the Edo period. The Daibutsu-den is the largest wooden building in the world; incredibly, the present structure, rebuilt in 1709, is a mere two-thirds of the size of the original.
The Daibutsu stands just over 16m high and consists of 437 tonnes of bronze and 130kg of gold. It is an image of Dainichi Nyorai (also known as Vairocana Buddha), the cosmic Buddha believed to give rise to all worlds and their respective Buddhas. Historians believe that Emperor Shōmu ordered the building of the Buddha as a charm against smallpox, which ravaged Japan in preceding years. Over the centuries the statue took quite a beating from earthquakes and fires, losing its head a couple of times (note the slight difference in colour between the head and the body).
As you circle the statue towards the back, you'll see a wooden column with a hole through its base. Popular belief maintains that those who can squeeze through the hole, which is exactly the same size as one of the Great Buddha's nostrils, are assured of enlightenment. There's usually a line of children waiting to give it a try and parents standing ready to snap their picture. A hint for bigger 'kids': try going through with one or both arms above your head – someone on either end to push and pull helps, too.
Except for the Daibutsu-den, most of Tōdai-ji's grounds can be visited free. Don't miss the Nandai-mon.