Lake Superior: Apostle Islands National Lakeshore is a 150 mile moderately trafficked out and back trail located near Bayfield, Wisconsin that features a cave. The trail is primarily used for scenic driving and whitewater kayaking and is accessible year-round.
This was another beautiful ride from September 2006. I would love to come back in the winter and see the ice caves.
Not sure if this would be the correct place to review, but I visited the ice caves in 2014 in this spot. It was the first time in 9 years it was cold enough to freeze the shore area on Lake Superior to see the caves, and if you ever have the chance to do this I would highly recommend it. It's definitely a natural wonder and far surpassed my expectations. It was a pretty long hike if you go as far as the farthest caves, which most people didn't. The ice formations are unreal and there were many bald eagles, as well as beautiful scenery and rock formations. There were spots in the caves where the ice was clear and you could look beneath you into the frozen lake, and many fun areas to explore and rocks to climb.