Budapest Children's Railway

The Gyermekvasút (English: Children's Railway) or Line 7 is a narrow gauge railway line in Budapest, which connects, via six stations, Széchenyihegy and Hűvösvölgy and is 11.2 kilometres (7.0 mi) long. It is one of Budapest's transport attractions located between the 2nd and 12th districts, most notable for that the service is provided by children under the supervision of adults. The former name of the line was Úttörővasút (Pioneer Railway, in reference to the communist scouts), and now the official designation is MÁV Zrt. Széchenyi-hegy Gyermekvasút. Except the train driver, all of the posts are operated by children aged 10–14 under adult supervision. It was the world's largest children's railway, until the expansion of one in Svobodny, Russia.

The Széchenyihegy terminus of the Gyermekvasút is a 250-metre (820 ft) walk from the upper terminus of the Budapest Cog Railway, whilst the Hűvösvölgy terminus is adjacent to the Budapest tram terminus of the same name. The two end stations of the line are Széchenyihegy and Hűvösvölgy, located 235 meters lower in sea level. The track is 11.7 km long, single-track with passing points at stations, not electrified. The trains cover the distance between the two terminals at a maximum permitted speed of 20 km/h in an average of 40-45 minutes (approx. 50 in summer, due to longer station dwells).

In 2015, the line was entered into the Guinness World Records as the longest railway line in the world where traffic and commercial service are operated by children. The railway transported approximately 800,000 passengers in 1961, 94,000 in 1993, and nearly 300,000 in 2013. The railway also acts as the season-opening event of the Carpathian Basin Small Railways' Day at second Saturday of April every year.