Mount Whitney, California
At 14,494 feet (4,418 meters) above sea level, California's Mount Whitney is the highest peak in the lower 48 states. Whitney is part of the Sierra Nevada, a fault-block mountain range formed when shifting tectonic plates led to the cracking and faulting of the Earth's surface.
Indonesia Mountains
A towering trail of steam and smoke issues from Mount Semeru in the distance while gaping Mount Bromo (middle left) quietly simmers in East Java, Indonesia. The Indonesian government estimates that during the last 400 years, 129 of the country's volcanoes have become active.
Mount Kinabalu, Malaysia
Fog obscures the summit of Malaysia's Mount Kinabalu, a 13,455-foot (4,101-meter) peak in northwestern East Malaysia. Formerly known as St. Peter's Mount, Kinabalu is the highest mountain in the Malay Archipelago.
Ben Nevis, Scotland
Overcast skies and mossy peaks overlook a lone hiker on Scotland's Ben Nevis mountain trail. Made up of ancient schist plated with volcanic rock, Ben Nevis is the highest mountain of the British Isles, at 4,406 feet (1,343 meters).
