Great cabin in a campground setting.
I went here a few years ago when my kids were a little younger and it was great. I believe it used to be a private camp that has now been converted to a public one. The cabins are a few hundred feet apart and there's access to the lake for swimming or boating. They have a main lodge which had some games and equipment for use. There's also an on site host with firewood for sale.
The interior of the cabins are spacious and could easily accommodate a large family. Its not too far from activities in Eagle River and there is a DNR center with some educational exhibits a few miles to the east. It was a really nice place to go to introduce the kids to the camping experience while they're young without having to pitch a tent or "rough it" right away.