Visiting the impressive Pyongyang metro is definitely a highlight of the capital. The network, which is made up of two lines, has a simultaneous function as a nuclear bunker in the event of a long-anticipated American invasion. Stations are deep below ground and you can even see blast doors that will close if Pyongyang ever comes under nuclear bombardment.
Nowadays a trip usually takes in several stations, although the entire network can be visited on specialist tours, disproving the long-standing rumours that much of the network isn't actually in use.