It is gd for traveller if just have 1-3 hrs to stay in Xian, it is near to the airport, and can spend 1-1.5 hrs in the underground museum. The underground museum has a mm automatic machine for providing briefing. Although it cannot compared with Qin Terra-cotta, but it is worthwhile for short time drop traveller to spend time.
It is 20 mins from airport.
It is a pity that one of the museum (I.e. The Southern part) is under maintaince n construction, so nothing can be seen there)
The entrance fee is RMB 80