These, dear friends, are the Mendenhall ice caves in Alaska. They exist only because a glacier is melting-- and as you can guess, glaciers don't keep on melting forever.
Over the past year, researchers have noticed strange ancient trees standing upright in the ice caves. Turns out that as it recedes, the glacier is unearthing forests which have been frozen for the last 1,000 years or so.
Explore these stellar havens for yourself on a trip to Alaska, or take a virtual journey with us on this icy Travel Tuesday.