Scotland contains the majority of mountainous terrain in the UK. The topography of Scotland is distinguished by the Highland Boundary Fault - a geological rock fracture - which traverses the Scottish mainland from Helensburgh to Stonehaven. The faultline separates two distinctively different physiographic regions; namely the Highlands to the north and west and the Lowlands to the south and east. The more rugged Highland region contains the majority of Scotland's mountainous terrain, including the highest peak, Ben Nevis.