The Glen is a curious little hike near Knocknarea in County Sligo. It’s called a “microvalley”. They warn you that the trail is “extremely muddy”, but what they mean is “under water” for much of its length haha.
The two way road leading to this hike is only wide enough for one car, meaning someone has to pull off if someone is coming in the opposite direction. One time when we did this, one of the front tires went off the edge of the cliff, leading to a few tense moments while I inquired as to whether the car was front or rear wheel drive (it was front wheel drive). We survived! We only went a little off the edge of a cliff.