The caves at Shimoni are limestone caves, several in number, once joined together and believed to extend some 5km inland. In Swahili, the word “Shimoni” means “the place of the hole”. In the caves can be found iron shackles on the walls, wooden crates likely used to transport slaves in, and old rusted pieces of chains. The metallic studs against which the slaves were held are now being swallowed by stalactites (a type of secondary mineral that hangs from the ceiling of limestone caves) and stalagmites (a type of secondary mineral that rises from the floor of a limestone cave) but some are still visible. They create a picture of what the conditions were like for the slaves held there. It is also believed that before slave trade peaked at the East African coast in the 18th and 19th centuries Shimoni caves were used as kayas, religious shrines, by the locals and as a hiding place when attacked by warring communities.