Tanzania has its own currency called the Tanzanian shilling. The flag of Tanzania features green, yellow, black and blue representing natural vegetation, mineral deposits, skin color of Tanzanians, and lakes/rivers/ocean. Common foods in Tanzania include rice, fruits, bread, vegetables, sea fish. Popular transportation in cities are overcrowded buses called "DALADALA". Tanzania is home to many languages and ethnic groups, with Swahili as the de facto national language. Popular tourist destinations include Serengeti National Park known for zebras, buffaloes, elephants, lions and monkeys. The population of Tanzania was last reported at 43.2 million in 2010.