The Amboni Caves are the most extensive limestone caves in East Africa. They are located 8 km in Kiomoni Village north of Tanga City in Tanzania off the Tanga-Mombasa road. The caves were formed about 150 million years ago during the Jurassic age. It covers an area of 234 km². According to researchers the area was under water some 20 million years ago. History has it that the caves were originally thought to extend 200 km or more. There are altogether ten caves but only one is used for guided tours. The Amboni caves, which are home to a large number of bats, were traditionally thought to be home to various spirits and are still used for worship and rituals by the locals.
Amboni Limited, a company which was then operating sisal plantations in Tanga Region acquired the area in 1892. The company notified the British colonial government about the caves who in turn declared the caves a conservation area in 1922.
It is not known when the caves were exactly discovered but reports indicate that ethnic groups such as the Segeju, Sambaa, Bondei and Digo who lived near the caves used it for prayers. In 1963, the then government of Tanganyika handed over the caves to the Department of Antiquities.
These caves have been subject of local legends and a number of mythical and awe-inspiring stories have been attributed to the caves. To the local people the caves are regarded as supernatural formations where supernatural powers commonly known as “Mizimu” are believed to have been residing since the caves formation. There are chambers treated as sacred chambers for worshiping some spirits. One of them is called “Mzimu wa Mabuvu”. Some believe that there is a powerful deity which can alleviate their sickness, sufferings or increase their fertility.