Canal features are an important part of many waterways, and locks are one of the most common. Locks are structures that allow boats to travel between different water levels, such as between a river and a canal. They are typically made up of two chambers with gates at each end, and when the gates are opened, the water level in the chamber is raised or lowered to match the water level of the other body of water. This allows boats to pass through without having to be towed or pushed.