Mýrdalssandur has a 35 km (22 mi)-long coast line, including Kötlutangi [ˈkʰœhtlʏˌtʰauɲcɪ], the southernmost point of the island of Iceland.

In the Middle Ages there was a fishing lake called Kerlingarfjörður [ˈcʰɛ(r)tliŋkarˌfjœrðʏr̥] at the mouth of the Múlakvísl.

These farms were, however, were mostly abandoned up to the 15th century, as a result of volcanic eruptions of the Katla, subsequent glacier runs and ashfall.

In 1168 a monks' monastery of the Augustinians was founded in the Þykkvabær í Veri [ˈθɪhkvaˌpaiːr iː ˈvɛːrɪ] on the Mýrdalssandur.

The monastery was dissolved, but it still existed for a long time as a rich farm until it was finally abandoned in 1945.