Xi'an is one of the easier large Chinese cities to move around in, because the historic core is still defined by the Ming city wall and the grid of streets inside it. The Bell Tower is the centre of that grid, four main avenues run out from it roughly to the four gates, and almost every sight in the old city can be reached on foot from that crossing. Everything else - the Terracotta Army, the high-speed rail station, the airport, the mountain - sits outside the wall and is reached by subway, taxi or a booked car.
The subway
The network has grown quickly and now links the old city with the rail stations, the northern and southern suburbs and the airport. Lines cross at the Bell Tower and at several points along the walls, fares are distance-based and very cheap, and every station has English signage and lettered exits. Tickets come from machines or by tapping a phone; stored-value transit cards work across the system and are worth buying if you are staying more than a couple of days. Trains run from around six in the morning until about eleven at night.
Taxis, bikes and buses
Metered taxis are plentiful and inexpensive by international standards, and the trips that matter - wall to railway station, wall to museum - are short. Drivers rarely speak English, so have the destination written in Chinese. Shared bicycles are everywhere and are the fastest way to cover the old city, since the streets inside the wall are flat and short. Buses fill the gaps but are harder to use without Chinese, and the city's tourist shuttle lines run to the Terracotta Army from the main rail station.
Practical notes
Avoid the morning and evening peaks in the central interchanges; the crush at the Bell Tower station between about half past seven and nine is real. For the Terracotta Army, either take the dedicated bus from the north square of the railway station or book a car, and leave early - the site is nearly two hours out and fills by mid-morning. If you are continuing to another city, note that Xi'an has two main rail stations and the high-speed trains to Beijing, Zhengzhou and Chengdu leave from the newer northern one; check which station your ticket names before setting out.
