Dyrahólaey, once known to some sailors as Cape Portland, is a cape that was once an island as you can see since the name ends with -ey which is Icelandic for island. Once Dyrhólaey was the southernmost point of Iceland, but about one hundred years ago there was this volcanic eruption and as a result of that massive amounts of sand got dumped by the volcano on a place several kilometers to the east. That point is called Hjörleifshöfði and will be the southernmost point of Iceland until the day come that the sea erodes the sand away, at current rates it will take some decades. Unless, of course, the volcano erupts again to add some sand at Hjörleifshöfði.