Today I got a great postcard from Hungary! The postcard shows a map of the Budapest Metro, the rapid transit system of the city of Budapest. Budapest is Hungary's capital city and its electrified underground railway system is the second oldest in the world. Its Line 1 is a UNESCO World Heritage Site. The system has a total of 4 lines, 52 stations, and an annual ridership of about 420 million passengers. Thanks Karolina!