Siskowit Mine, Isle Royale National Park, Keweenaw County, Michigan, USA
The only very clear mine shaft has one bowl that could be a collapsed mine shaft on either side of it (east-west).
Could be the foundation of some structure in the background, but the foreground is a bowl about 15 feet in diameter to the left (west) of the much deeper bowl.
Tailings pile is fairly visible from the shoreline of Rock Harbor, more or less directly across from the dock on Mott Island.
From the Three Mile Trail along Rock Harbor going east, you'll pass a very short (10 yd) trail to the tailings pile on the right before you come to the shafts on the left side of the trail.
The Three Mile Trail goes right through the Siskowit Mine. Shafts are on the North side of the trail; tailings pile is on the south side.