I absolutely love this now-and-then snapshot of what is now the busiest subway system in the world. The picture on the left is from the first edition of Lonely Planet’s guide to China in 1984; the one on the right is from the 13th edition, released this year. That’s only a 29 year gap – quite astounding!

Source: two tweets from Daniel McCrohan, a writer for Lonely Planet’s China and Beijing guides. 1984 and 2013.