A view over makuti thatched roofs to the estuary that divides Lamu Island from uninhabited Manda Island, which has no permanent source of sweet groundwater.Mashuas, the small wooden sailing boats of the East African Coast (colloquially known to visitors as dhows), carry passengers and cargo from nearby Kenya mainland to the island.The rooftop verandahs on some of the buildings are used as sleeping quarters in hot weather.Situated 150 miles north-northeast of Mombasa, Lamu town dates from the 15th century AD. The island's importance lies in the fact that it has the only certain source of sweet groundwater in the entire district. The town was declared a World Heritage Site by UNESCO in 2001 because it is the oldest and best preserved Swahili settlement in East Africa. Moreover, its architecture and urban development graphically demonstrates the diverse cultural influences that came together over many centuries to produce a distinctively local Swahili style and culture.