One of the most popular places to take aerial wedding photos in Taiwan is at this romantic heart-shaped stone structure. While it might look like modern artistic earthworks — perhaps even designed with postcards and wedding photographs in mind — the reality is something much different, and far less romantic.

These stone sea walls — like many that are found along the coast of Taiwan — are actually not modern at all; they're ancient constructions elaborately designed to herd fish. Unbeknownst to many visiting couples, that idyllic twin-heart edifice is hardly a symbol of love. It was originally built as an anchovy killing field, reports The Smithsonian.

The story behind Taiwan's ancient fish traps is quite fascinating. Those that still survive along the country's coast are leftover remnants of fishing weirs that date to the late 1600s and early 1700s, when fishing in Taiwan was a major undertaking. Fisherman were known to use them to catch everything from silver-stripe round herring, to Indian anchovy, to greater amberjack and more, with hauls that would regularly exceed 1,000 pounds. Some of the structures are so complex that they stretch for miles and probably took decades of careful planning to create.

The general principle at play involves the tides. At high tides, the walls of the weirs are entirely submerged, allowing fish to swim over them. But as the tide recedes, fish become trapped and easy pickings for fisherman walking along the walls with nets, spears or baskets. Fish could be literally scooped out of the ocean by the thousands. Many of the weirs also incorporated curves, which takes advantage of a known tendency for fish to turn around when they hit a curved surface. The weirs were constructed to herd the fish as needed.

It was a brilliant setup, one that was unparalleled for catching fish until as recently as the 1950s, when motorized fishing boats and enhanced fishery technology made maintaining the weirs impractical and unnecessary. By now, most of these ancient structures have fallen into disrepair, but some of them — mostly those in Penghu County Taoyuan City and Miaoli County — are maintained for their historical significance (and, undoubtedly, for the sake of all those picturesque wedding shots).