The drawbridge is the only one of its type in northwest Florida. A bridge over a navigable waterway must allow boats and ships to cross its path. The type of movable bridge that most people think of as a draw bridge is similar to those that spanned medieval castle moats. Technically called "bascule bridges" from the French word for seesaw, Movable bridges are relatively rare because they are more expensive to operate and maintain than stationary bridges. This is a swing bridge which is supported on vertical pivots, and the movable span rotates horizontally to open the bridge.