The River Welland used to split into two channels in the heart of Crowland, Lincolnshire, and in 1360 the townspeople arranged to bridge it with this unique triple arch, which elegantly spanned the streams at the point of their divergence, allowing pedestrians to reach any of the three shores by a single structure. The alternative would have been to build three separate bridges.
The rivers were re-routed in the 1600s, so now the bridge stands in the center of town as a monument to the ingenuity of its inhabitants. It’s known as Trinity Bridge.
From the ArtefactPorn subreddit.