Locks
A lock is a hydraulic engineering project that allows vessels to travel up or down rivers or seas in areas where there are barriers. It acts as a veritable water elevator, helping ships cross rivers or canals where the terrain is uneven. This unevenness can be caused by the construction of a dam or a hydroelectric plant, for example, or of natural origin, such as waterfalls. A lock is nothing more than a large concrete chamber with two enormous steel gates.