Jokulsarlon is a glacial lake at the base of the Breidamurkur glacier which flows directly into the Atlantic under a road bridge. It is an ever changing environment and I have visited it both in winter and summer. In winter the lake is frozen, with icebergs just at the mouth of the lake but in summer the icebergs float around in the unfrozen lake. They exhibit a variety of colours from black to white to turquoise blue and are often stripy.