formed by volcanic activity over 50 million years ago, the Giants Causeway is Irelands first World Heritage Site. In Irish folklore, epic hero Finn McCool was said to have built the causeway in order to challenge a neighbouring giant.
Located in northern California, Lassen Volcanic National Park is a true winter wonderland. Silent, snow-covered volcanoes hide magma beneath their calm surfaces – clues to the area’s three million years of volcanic activity show up in steam vents, boiling springs and bubbling mudpots. Even in winter, these hydrothermal (“hot water”) features melt nearby snow and ice. Photo by Mike Matiasek, National Park Service.