The Azores are steep-sided volcanic seamounts that drop rapidly 1000 meters (about 3300 feet) to a plateau. Cores taken from the plateau and other evidence shows that this area has been an undersea plateau for millions of years. Ancient indicators, i.e. relict beaches, marine deposits, and wave cut-terraces, of Pleistocene shorelines and sea level show that the Azores Islands have not subsided to any significant degree. Instead, they demonstrate that some of these islands have actually risen during the Late and Middle Pleistocene. This is evidenced by relict, Pleistocene wave-cut platforms and beach sediments that now lie well above current sea level. For example, they have been found on Flores Island at elevations of 15-20, 35-45, ~100, and ~250 meters above current sea level.