Permafrost Research Tunnel, Alaska

A field research site for the Army Corps of Engineers featuring a 360-ft long horizontal shaft excavated in permanently frozen ground. The tunnel is between 6 to 8 feet high, 13 to 16 feet wide, and around 49 feet deep. The ice therein contains assorted fossils, plant remains, insects, macrobiotics, and bacteria, some of which are over 40,000 years old. Operated by the Army Corps Cold Regions Research Lab, based in Hanover, New Hampshire (where there is little in the way of permafrost). The lab operates another Alaska field station a few miles away, off Farmers Loop Road, northeast of Fairbanks, for testing the response of pilings and other foundations to permafrost creep and frost-jacking.