Reynisfjara is the southernmost beach in Iceland. At Reynisfjara you can explore Hálsanefshellir, which is a remarkable sea cave made of columnar basalt. It lies on the southwestern side of Reynisfjall where the mountain meets a great expanse of black beach. Also, from there you can see Reynisdrangar - a collection of 66 m high rock pillars that rise out of the sea and are of the same geological formation as Reynisfjall (they are believed to be troll caught by sunlight).