Hungary

In Budapest, two that connect. The Children's Railway runs about eleven kilometres through the Buda Hills with children aged ten to fourteen doing every job except driving — Guinness recognised it in 2015 as the longest railway in the world run by children. The Cog-wheel Railway is the 1874 rack line that gets you to its upper terminus, and is still an ordinary part of the city tram network. Their termini are 250 metres apart. In the north-east, the Lillafüred Forest Railway runs 14 kilometres on 760 mm gauge from Miskolc into the Bükk hills, to a palace hotel, a lake, a waterfall and two caves. Further east, in the Zemplén Mountains, the Pálháza Forest Railway of 1888, Hungary's oldest forest railway, runs nine kilometres from Pálháza through a tunnel under a hunting lodge to the woods at Rostalló. North of Budapest, the Danube Bend Railway is the country's first line, opened from Pest to Vác in 1846, and runs an hourly train along the river to Szob on the Slovak border in under an hour. On the Great Plain, the Zsuzsi Forest Railway runs 16.6 kilometres from Debrecen into the Erdőspuszta woods on summer Wednesdays and weekends, on a line laid in 1882 to a gauge used nowhere else in Hungary.

No — and this is the thing most often got wrong. Children aged 10 to 14 hold every other operating post: signallers, pointsmen, guards, announcers, traffic managers, cashiers and ticket inspectors, rotating through each in turn. The drivers and engineers are adults, and everything is supervised. Children volunteer, apply in the fourth grade, and must pass a medical aptitude test, complete a training course and show good school marks. It is heavily oversubscribed.

On one of them. The Cog-wheel Railway is tram line 60 and is fully inside the BKK fare system — any Budapest ticket, travelcard or Budapest Card is valid, with no supplement. The Children's Railway is not: it is run by MÁV, sits outside city ticketing, and takes cash in Hungarian forints only — no cards. Carry cash if you are doing the circuit. The Libegő chairlift is also ticketed separately.

The Cog-wheel Railway runs every day of the year, roughly 05:00 to 23:00. The Children's Railway runs daily from May to August and daily except Mondays from September to April. The chairlift closes on alternate Mondays and in high wind — so if you want the full circuit, avoid Mondays altogether. Late October into early November is the best fortnight, when the beech woods both lines climb through turn completely.