Glaciers are some of the most dramatic natural formations on Earth. Glaciers develop over many years - the result of compacted snow transforming into hard ice under incredible pressure. They exist in cold climates all over the world, including several locations in the United States. They're among the natural wonders threatened by climate change, with many of the world's glaciers shrinking in size over the last few decades.
While most people have seen a fair share of beautiful glacier pictures, not many know what glaciers look like on the inside. A glacier's interior is as breathtaking as its facade, sometimes even more so. Some glaciers also have caves within them, allowing travelers and adventure junkies to climb inside and explore the interior of these frozen masses. These photos from deep within glaciers illuminate the unique beauty of our planet's icy habitats.