Photo: Tunnel Tree on the Crescent Meadow Road, a photo taken on July 17, 1940 by George A Grant, from National Park Service Historic Photograph Collection.
The Tunnel Log is a tunnel cut through a fallen giant sequoia tree in Sequoia National Park, in the southern Sierra Nevada, east of Visalia, California, in the United States of America. The tree, which measured 275 feet (84 m) tall and 21 feet (6.4 m) in diameter, fell across a park road in 1937 due to some natural causes. The next year, a crew cut out an 8-foot (2.4 m) tall, 17-foot (5.2 m) wide tunnel through the trunk of the sequoia to make the road passable.
Photo 2: Tunnel Log in American Grand Forest, photo by Martin Leupold, taken in July 2005 and released as Public Domain Photo.