Thirteen dynasties established their capitals here—back then it was Chang'an, the eastern gateway of the Silk Road, and during the Tang Dynasty, one of the world's largest cities. Its signature attraction, the Terracotta Warriors, was accidentally discovered in 1974 by farmers digging a well; the 13.74-kilometer Ming Dynasty city wall is so well-preserved you can cycle around its entire perimeter.
The confidence of the Tang Dynasty lives on in Xi'an's streets today: the Muslim Quarter behind the Drum Tower, lit by lanterns; the 2,100-meter Tang-style Grand Tang Mall, aglow with lights; and the sound of dough being slapped to make biangbiang noodles—a character with over 50 strokes.
Give this city three days: one for the eastern sites of the Terracotta Warriors and Huaqing Palace, one for the city wall, Big Wild Goose Pagoda, and the museums, and another day dedicated to eating in the alleys behind the Drum Tower.