Apo Reef two lagoon systems, the north and south lagoons which are bounded by narrow reef platforms. It is a almost triangular northern and southern atoll-like reefs separated by a deep channel that is open to the west. The channel runs east to west from deep with a fine white sand bottom, numerous mounds and patches of branching corals under the deep blue water. The north lagoon is an enclosed triangular coral reef platform partly exposed during low tide. It is relatively shallow with depths of about . While the south lagoon is an inverted triangular coral platform enclosed on two sides
Open-air Water Museum hall, a recreation area and an open-air cinema. There are many water channels on the site. Open-air Water Museum The Open-air Water Museum () is located in the city of Edessa, Central Macedonia, Greece. In the early 20th century there were many water-powered workshops in the city. In 1991 the Municipality of Edessa decided to improve and develop the Mills area, the Kannavourgio and the ‘Estia’ works, by establishing an open air, water-power museum, and creating recreation areas. The Open-Air Water Museum, which opened early in 2000, aims to acquaint visitors with the history of water-power from the workshops of