I think many people come to Nara for Todai-ji and stay for the deer. Because of this, the deer are often associated with the famous temple, but the actual reason they’re considered sacred is because the deer are believed to be the messengers of the gods enshrined at Kasuga Shrine and that inhabit the area.
The shrine is on the east side of the park. A long, upward sloping path leads up to the shrine from the park. Once there, you can enjoy the striking, red architecture and the many lanterns that have been donated to the shrine over the years.
Like Todai-ji, it is an UNESCO World Heritage Site. The shrine was established in the 700’s to protect Nara and, like Ise Shrine, is rebuilt every 20 years to renew its divinity. This process has been repeated for over 1000 years.