(Photo: Catherine Morgan)
Barra is a 23-square mile island off the western coast of Scotland. It has an airport with three marked runways. It conducts regularly scheduled flights. What makes those flights unique is that the schedule takes into account the tide. That's because during high tide, the sea submerges the runways.
According to this history of the Barra Airport, commercial air service to Barra began in 1936. A wide beach called Traigh Mhòr proved to be the ideal landing strip for the rocky island. A passenger terminal was built in 1978.
Here's a video of a plane landing on one of Barra Airport's beach runways.
-via Marilyn Terrell