Wichai Prasit Fort is an ancient fortress on the banks of the Chao Phraya River that has played a crucial role in protecting the capital since the Ayutthaya period. Located at the mouth of the Bangkok Yai Canal, it was once a key strategic point for inspecting vessels passing through. Today, the fort is under the care of the Royal Thai Navy and continues to be used as the site for firing royal gun salutes during important ceremonies. With its architectural features of octagonal masonry walls, the fort remains an elegant and powerful symbol that stands the test of time.