Freda
Just down the road from Redridge is the town of Freda, MI. This place was once home to the Champion Stamp Mill which processed ore from the nearby Champion mines and offloaded it to freighters. It closed down in 1967 and its machinery was scrapped. Soon after the bulk of its structures were demolished, though there are still significant areas to explore.
The main mill today is just a foundation. It's situated about 30 feet or so above the water on a cliff so naturally this makes for an awesome spot to have a bonfire or just watch the sunset. To the southeast are a few buildings that haven't been knocked down yet. If you continue through those buildings and up the hill you will reach a dirt road. Walk left a little ways and you'll find a tunnel that goes into a hill to your left. I highly recommend checking this out if you have hiking boots as it divides into a bunch of other tunnels. I don't have pictures but it's really cool. Trust me.
To the southwest of the mill is a large smokestack that you can climb into. It also makes crazy sounds if you yell or shoot fireworks off in it, the latter of which I don't recommend. Your ears will ring for a week.
My favorite part about this place has nothing to do with the ruins at all though. Once you get down the cliff to the shore at lake level, you can walk northeast to a bunch of big sandstone cliffs. If you take your shoes off, hug the wall and wade around the cliff, you'll come to a stone beach in a cove with a small waterfall (depending on rainfall) between the cliffs. Not a lot of people know about this but it's by far one of my favorite hidden gems for bonfires. If you're going to start a fire though bring your own wood. The driftwood in the cove is usually wet.
During the winter, lake ice builds up over the beach and forms huge ice hills (and sometime ice volcanoes) that extend a long distance to the north and south. I've also seen some cool pseudo-ice caves here.
Some things to note: Be careful when walking down or near the cliff. Erosion has made the slope relatively unstable in some areas. When walking around the sandstone cliffs, be aware that some of the rocks may be slippery due to algae. Also don't try to skirt the cliffs during a storm or anything. Use your head. When you're over by the smokestack, don't go further south. That's private property. Lastly, if you're checking out the ice formations in the winter, don't walk out on them unless it's been consistently cold for a long time, you have a friend with you, and you know what you're doing!
To get here from Houghton, head west through downtown, through the yooper loop and west on M-26. After a quarter mile or so take a right on Houghton Canal Road. Continue for 5 miles until you get to Schmidt's Corner Bar and take a left on Liminga Road. Continue for 9 miles. You'll pass by Redridge and Beacon Hill. When you get into Freda, turn left on Superior View Road and park in the lot at the end of it. It looks like somebody's personal parking lot but it's not. The parking lot is pretty high above the ruins. To get down, follow the trail west that goes down a steep hill and turn left once you get to the bottom.
Some useful links:
https://en.wikipedia.org/wiki/Freda,_Michigan
http://www.stantontownship.com/history/freda/
Thanks to Jon Clark for the winter ice hill shot!