The Gyermekvasút (English: Children's Railway) or Line 7 is a narrow gauge railway line in Budapest, which connects Széchenyihegy and H?vösvölgy and is 11.2 kilometres (7.0 mi) long. The former name of the line was Úttör?vasút (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[1] under adult supervision. It is the world's largest children's railway.