Brunei is a country in Asia on the island of Borneo. The revenues from oil and natural gas led to immense wealth in Brunei and allowed the country to grant its citizens the most extensive tax relief. Brunei has a tropical rainforest climate with average temperatures of 27 degrees Celsius. There is a strict ban on alcohol in the strictly Islamic state. The Iban, a tribe of indigenous people, still live in their characteristic longhouses. Of tourist interest in the capital is the "water village" Kampong Ayer, built on stilts. It is overlooked by the golden dome of the mighty Omar Ali Saifuddin Mosque on an artificial lagoon.