Coral World Underwater Observatory Eilat

The park was founded in 1974 by the zoologist and marine biologist David Friedman. Also the idea of the observatory was planned in 1972, it took careful planning to create the observatory without harming the natural environment. The observatory was built completely on land, which was then flooded with water from the Red Sea using armory parts and other metals. The base of the observatory was connected to large iron chains, and after the observatory was placed many corals were planted on and around the observatory in order to repair the damage that was done during the making of the observatory. The coral reef around the observatory flourished and became a major feeding spot for many fish and other marine wildlife, both carnivorous and herbivore.

Source: https://en.wikipedia.org/wiki/Coral_World_Underwater_Observatory