After leaving Blue Lagoon, head towards Grindavík, a small town on the southern coast. The barren, mossy landscape along the drive is incredible. On the left is Mount Thorbjorn. Þorbjörn is a hyaloclastite ridge formed during a subglacial eruption. This phenomenon occurs when the molten lava and gases of a glacier-covered volcano violently mixes with snow and ice. The result is the magma fractures into glass.