The most memorable feature of Zanzibar houses are the spectacular carved Zanzibar doors. These Zanzibar doors signify the aspirations of their original owners, their socio-economic status, their ethnicity and customs. The greater the wealth and social position of the house owner, the larger and more elaborately carved their front door would be. Many of the Zanzibar doors have been carved with Arabic influences.
(http://www.tanzanianfineart.com/about-zanzibar-doors/)