Giants kettle (Marmitas de Gigante)

Guadiana River Natural Park, Alentejo, Portugal

Giants kettle ("Marmitas de Gigante" in portuguese), also known as giants cauldrons or potholes, are cavities or holes which appear to have been drilled in the surrounding rocks by eddying currents of water bearing stones, gravel and other detrital matter.

There are several formations of these along the Guadiana River, on the known as the "Wolf´s Leap" site.