Those rocks are formed as a consequence of strong tidal forces for centuries. The most interesting part of those rocks, the base, is covered by the water twice per day but it is possible to see them in full shape during the low tide.
During the low tide, Hopewell Rocks look like they are from another world. Their almost impossible shape make them to look like they are actually made by humans. Some of them look like huge heads with very big noses.
Images sources : EverySpoon
