Arkadiko Bridge, Argolis, Greece

The low culvert of rough limestone blocks near the village of Arkadiko in the Peloponnese, built in the Late Bronze Age, roughly 1300 to 1190 BC. It is one of the oldest arch bridges still in use anywhere. There is no true arch here. The Mycenaeans built a corbel arch, stepping each course of stones slightly inward until the two sides met, and the dry-laid walls have held without mortar for more than three thousand years. It carried a road built for chariots between Tiryns and Epidaurus, and the stone curbs that kept wheels off the edge still line its top. Local people still walk across it.