Ile des Cendres is a group of submarine volcanoes located off the southeast coast of Vietnam. It consists of two submarine cinder cones that formed ephemeral islands during an eruption in 1923 and two submarine lava cones of uncertain age. The 1923 eruption produced two small islands, one about 30 m (98 ft) high and about 450 m (1,476 ft) long, and the other only 30 m (98 ft) wide and 30 cm (12 in) high. A third submarine cone reached to within 20 m (66 ft) of the surface.