Although complexity of local government differs depending on size and development of each emirate, most (such as Abu Dhabi, Dubai, Sharjah and Ajman) have their own executive councils chaired by their respective rulers and possessing various departments reflective of federal ministries. Various autonomous agencies also exist such as the Environment Agency, Tourism Authority, Authority for Culture and Heritage, and the Health Authority. Some emirates such as Abu Dhabi may also be divided into two municipalities (the Western and Eastern regions) and its main cities of Abu Dhabi and Al Ain are also administered by their own municipalities with a municipal council. Abu Dhabi and Sharjah also have their own National Consultative Councils with similar local duties and role as the Federal National Council.