In the early 1900s a light railway (36-inch gauge) was built and operated by an American company from a point outside the Arab Fort in Zanzibar Town, along the seafront and up the coast to the village of Bububu. Construction began in 1904 and ended in 1905, and the service was used mainly by local people, but a special first-class coach was joined to the train so that passengers from the steamers that put in to Zanzibar could get a brief glimpse of the island. The line was closed in 1928, but railway buffs can still see the remains of bridges and embankments, as today's main road between Zanzibar Town and Bububu runs parallel to the line (and in some cases over it). Bits of the original track can be seen at Bububu.

In his book Sketches in Mafeking and East Africa (published in 1907), Lord Robert Baden-Powell quotes from a description of the Zanzibar train by an American writer called Miss Kirkland. 'Have you ever been to Bu Bu Bu? If not, do not call yourself a travelled person,' she wrote. 'Bu Bu Bu is a settlement in a shady grove on the island of Zanzibar, and is the terminus of a new and important railroad – six and a half miles long.'

It has been suggested that the name Bububu comes from the sound made by the train's hooter, but maps dating from before the building of the railway show the village already had this title. It is more likely that the name was inspired by the sound of the freshwater springs which bubble to the surface just outside the village. Most of Zanzibar Town's water supply still comes from here.