Zanzibar is the Swahili name of the island, but it originates from the Arabic name زنجبار (zanjibār), which actually means "land of the blacks", zang means black, bâr means coast. Zanzibar was inhabited by humans at least since the Later Stone Age, the oldest remains are dated 20,000 years BP. There are some theories that the Greek already knew about the island. The coast and the island were inhabited by Bantu speakers since almost 2,000 BP. Fukuchani Cave, which is listed below, revealed an agricultural and fishing community from the 6th century or earlier. The Swahili people served as intermediaries and facilitators to Persian, Indian, and Arab merchants and traders. Their culture was based on the Arabic culture, and they used Arabic script. Zanzibar was inhabited by autonomous city-states, as was the East African coast.
The begin of colonization is the year 1498 when the Portuguese Vasco da Gama discovered the island. In 1503 or 1504, Captain Ruy Lourenço Ravasco Marques landed and demanded and received tribute from the sultan, in exchange for peace, Zanzibar became part of the Portuguese Empire. In the mid 17th century the Swahili elites in Mombasa and on Zanzibar invited Omani aristocrats to assist them in driving the Europeans out. This worked in a way, from 1698 the Portuguese were gone, the island was under the rule of the Sultanate of Oman.
East Africa was a source of slaves since the Middle Ages. Arabic slave traders travelled down the coast and either bought slaves from local rulers or just caught the locals. Later the British established a massive slave trade which became famous as triangular trade. British industrial products were traded for slaves in Africa, the slaves were traded for raw products, mostly cotton, in America, and those raw products were traded for industrial products back in Britain. To make one thing clear: both the Arabs and the Brits actually did not enslave the people, this was done by the local black slave traders, who captured and sold them. Zanzibar was probably the main marketplace for selling slaves, they were brought to the island and then auctioned to the international slave traders.
Britain abolished slavery in 1833, France in 1848, and the U.S.A. finally in 1865. In 1887 Zanzibar became a protectorate of Britain, which should have ended the slave trade theoretically. The Zanzibar Slave Market was closed by the Sultan as late as 1907. But while being illegal, clandestine slave trade went on until the 1940s. It was 1948 when the United Nations finally declared slavery illegal under the Universal Rights of Man. And Mauretania was the last country in Africa which finally abolished slavery in 1981. We all know that slavery exists until today in most countries, both work and sex slaves. At least the use of caves for "storage" has ended, as far as we know.
Zanzibar has a tropical monsoon climate, with the main wet season March to May and a secondary wet season in November and December. Much of the island consists of limestone, either hard and dense crystalline Miocene limestone consisting of broken limestone, shell fragments and bands of flint, or Quaternary limestone, forming the island’s main underground aquifer. As a result the island has numerous karstified areas with underground drainage, and a great numer of mostly small caves. Caves reaching the groundwater were of great importance, they were used as wells, first by collecting water by hand, later pumps were installed. The limestone lies on a basement of bluish grey to bluish green marls, sandy clays and clayey sands. It is on the surface on the western side of the island north of the capital Zanzibar city. Here drainage on the surface, but also contact karst at the borders can be found.
We listed several caves as show caves, though there are strictly speaking no show caves with concrete trails and electric light. However, the caves have trails, staircases, even railings, if necessary, guided tours and open hours and entrance fees, which is a lot for a third world country. Nevertheless, the border to semi-wild caves is close.