Indonesia

Lake Toba is located in the middle of the northern part of the island of Sumatra, occupying the caldera of a supervolcano. The lake is about 100 km (62 mi) long, 30 km (19 mi) wide, and up to 505 m (1,657 ft) deep. It is the largest lake in Indonesia and the largest volcanic lake in the world. Lake Toba is the site of a supervolcanic eruption estimated at a Volcanic Explosivity Index (VEI) of 8, the largest recorded value on the index. Recent advances in dating methods suggest the date was 74,000 years ago and that it represented a climate-changing event. It is the largest-known explosive eruption on earth in the last 25 million years.

The Sea Temple of Pura Luhur at Uluwatu in south Bali dates back to the 11th century.

A mosque in Medan, the capital and largest city of the Indonesian province of North Sumatra.

Lake Toba is located in the middle of the northern part of the island of Sumatra, occupying the caldera of a supervolcano. The lake is about 100 km (62 mi) long, 30 km (19 mi) wide, and up to 505 m (1,657 ft) deep. It is the largest lake in Indonesia and the largest volcanic lake in the world. Lake Toba is the site of a supervolcanic eruption estimated at a Volcanic Explosivity Index (VEI) of 8, the largest recorded value on the index. Recent advances in dating methods suggest the date was 74,000 years ago and that it represented a climate-changing event. It is the largest-known explosive eruption on earth in the last 25 million years.

Ashmore Island (actually composed of three reef islets) is part of Ashmore Reef National Nature Reserve, established in August 1983, and covers 583 sq km (225 sq mi). It is of significant biodiversity value since it lies in the flow of the Indonesian Throughflow ocean current from the Pacific Ocean through the Malay archipelago to the Indian Ocean. It is also in a surface current west from the Arafura Sea and Timor Sea. The Reserve comprises several marine habitats, including seagrass meadows, intertidal sand flats, coral reef flats, and lagoons, and supports an important and diverse range of species, including 14 species of sea snakes, a population of dugong that may be genetically distinct, a diverse marine invertebrate fauna, and many endemic species, especially of sea snakes and molluscs. There are feeding and nesting sites for various turtle species. It also serves as a bird sanctuary and has 50,000 breeding pairs of various kinds of seabirds. A high abundance and diversity of sea cucumbers, over-exploited on other reefs in the region, is present, with 45 species recorded. This astronaut photo from 1992 shows that the reef making up the island is not continuous but has several breaks that allow for current and sediment inflow. Image courtesy of NASA.

The thick brown plume of ash, steam, and volcanic gas rising from Anak Krakatau in this true-color image is a common sight at the volcano. Responsible for one of the largest and most destructive eruptions in Indonesia's history (1883), Krakatau still erupts frequently. For this reason, the volcano is one of 100 that NASA automatically monitors by satellite. Photo courtesy of NASA.