The Neptune Memorial Reef was first opened in 2007 and is still under construction. This interesting cemetery is the biggest man-made reef of the world with a surface of 6,47 hectares, bigger than seven football fields. When its construction is finished, it is predicted to have 5.000 columns and each of them will be weighing around 5 tons. It is expected to have a cost of 1,5 million dollars when the construction ends.