Yes, I mean, literally, walking through a tree, not through the forest. This photo was taken at Kings Canyon National Park in the southern Sierra Nevada Mountains in central California, east of Fresno. It is north of and contiguous with Sequoia National Park. This tunnel bored through a tree giant sequoia. The person at the other end of the tunnel is my son, Pete, who is about 6' tall. That should give you an idea of the size of this tunnel.
Kings Canyon National Park, as well as Sequoia National Park, is home to a grove of giant sequoia trees known as the General Grant Grove named after President Ulysses S. Grant. Most prominent of the giant sequoias found in the park is "General Grant," the third largest tree in the world, dating back some 1,650 years. It is 268.1 feet tall, 34.2 feet in diameter and 107.1 feet in circumference at its base. That is one BIG tree. It's actually less than 7 feet shorter than "General Sherman," currently ranked as the largest giant sequoia and tree in the world.
It is awe inspiring to stand amid these giants that have not only endured more than a millennium, but some have endured two or more millennia. There is actually one tree (not a sequoia) that is estimated to be well over 5,000 years old. This tree is in the United States, but it's location is a very tightly held secret for security and preservation reasons.
I imagine the National Park Service fears that if its location becomes known to the general public, the tree might suffer the same fate as the, somewhat, famous landmark single tree on One Tree Hill in Auckland, New Zealand. It was attacked twice by activists, once in 1994 and again in 2000. The tree did not survive the second attack, was removed and has yet to be replaced. I was fortunate enough to visit One Tree Hill and the tree in January 1991.
There are few places where you can walk through or drive through trees other than California. I also drove through a giant redwood once in the Pacific coastal redwood groves. Regardless of whether you walk or drive through a tree, it's an awesome experience. Just think of all that has happened in our world since some of these trees first sprouted roots.