1067-20 - Snorkelers on the surface of a blue hole. Virgin Blue Hole dive site, Palau, Micronesia, Pacific Ocean. More info: Blue holes such as this are submerged limestone sink holes.
911-6829 - A twenty ton ice explorer truck owned and run by Arngrimur Hermannsson ( Arni), next to a sink hole for meltwater (moulin), Langjokull ice cap, Iceland, Polar Regions
911-6825 - A twenty ton ice explorer truck owned and run by Arngrimur Hermannsson (Arni), taking tourists onto the Langjokull ice cap, Iceland, Polar Regions
911-6830 - A twenty ton ice explorer truck owned and run by Arngrimur Hermannsson ( Arni), next to a sink hole for meltwater (moulin), Langjokull ice cap, Iceland, Polar Regions