The metro system in Beijing is one of the largest in the world and the fastest way to cross the city by far. With more than 20 lines and signage in both Chinese and English, it is surprisingly easy to navigate even on a first visit. Trains run from roughly 5:30 a.m. until 11 p.m., with peak hours getting genuinely crowded around 8 a.m. and 6 p.m. on weekdays. Fares are distance-based and start at 3 RMB; most rides across the city centre stay under 6 RMB. For visitors, the best approach is to buy a Yikatong transport card at any station for a 20 RMB deposit. The card works on the metro, the buses, and many taxis. Line 1 runs east–west and connects most of the major sights: Tiananmen Square, the Forbidden City, the Wangfujing shopping street. Line 2 follows the old city wall in a loop. The airport express line from Terminal 3 reaches the city centre in 25 minutes.