The Molli (German: Mecklenburgische Bäderbahn "Molli") short: (MBB) is a narrow-gauge steam-powered railway in Mecklenburg, running on gauge track. It operates between Bad Doberan, Heiligendamm and Kühlungsborn West over a total distance of 15.4 km with a running time of 40 minutes. Within Bad Doberan the line runs through the street, and later along a linden tree-lined avenue. Between Heiligendamm and Kühlungsborn the tracks run parallel to the Baltic Sea beach across fields.
From May 30th, 2007 to June 9th, 2007, the train service was cancelled owing to the G8-summit at Heiligendamm. The tracks between Heiligendamm and Bad Doberan were damaged during the summit so that the train services were cancelled two further days.
Owing to the low tourist demand in the winter, half of the trains are cancelled and are replaced by the so-called Mollibus. This bus line is the number 121 and drives from Rostock Bus station via Bad Doberan, Heiligendamm and Kühlungsborn to Rerik. It is operated by the Küstenbus GmbH. Only the buses between Bad Doberan and Kühlungsborn are called Mollibus. Of course not all buses drive the whole route. Some buses operate in the summer also in the morning and evening because of the low demand.
Since the 1990s, the Molli has also been one of the main ways of getting to the Zappanale, a festival held every summer dedicated to the music of Frank Zappa. The site for the past few years has been the Gallopenrennbahn (racecourse) about halfway between Bad Doberan and the coast. It is not very often that fans get to a rock festival by steam train.