General Zhang Xueliang's Official Residence is a useful stop for travellers interested in Xi'an beyond the imperial and Tang-dynasty story. Zhang was a central figure in the Xi'an Incident of 1936, and the residence helps place that tense Republican-era episode in a real urban setting.
The site is more sober than spectacular. Expect period rooms, photographs, and political history rather than grand architecture. It pairs well with other twentieth-century history sites in Xi'an if you want a fuller picture of the city's modern layers.