Giant Wild Goose Pagoda is a very cool historical site to visit in Xi'an. It was built in the seventh century to house Buddhist scriptures, statues, and other relics that were brought back to China by the Buddhist scholar and traveler Xuanzang. Extended, rebuilt, and renovated over the years, the pagoda currently leans noticeably to the side.
There is an interesting legend about how the pagoda got its name. A group of Buddhist monks had no meat to eat (then, as now, not all Buddhists were vegetarian). As some wild geese flew overhead, one monk hoped that the Bodhisattva would provide some meat—at which point, the front goose fell to the ground. The monks believed this was a sign that they should be more pious. They decided to give up eating meat, and established a pagoda at the point where the goose had fallen.
Visitors can pay to climb to the top of the pagoda. We took a pass on the day we were there because there were so many tourists waiting to buy tickets, but the view from the top is said to be excellent.