A good 90% of visitors to Xi'an come for the famed Terracotta Warriors. Don't bother. OK, do bother, it's nice to say you've seen them, but what the brochures describe as 'The Eighth Wonder of the World' is really little more than an unspectacular bunch of mannequins in a big hangar.
Once you're actually there, they just don't have the impact they have in the photos. Sorry. There's plenty other stuff in Xi'an to keep you happy instead.
By bus from the train station - quite far out from the city centre