The Roads That Disappear Under the Sea: How Tidal Roads Work

Most roads are designed to keep water away. But in a few extraordinary places, the road itself disappears beneath the sea. These tidal causeways are built across shallow coastal waters and are covered by the incoming tide at certain times. When the sea retreats, the route re-emerges and becomes usable again. One of the best-known examples is the Passage du Gois in France, a causeway connecting Noirmoutier Island with the mainland. It is a spectacular reminder that some roads are controlled not by traffic lights, but by the rhythm of the ocean.