Even though we seem to have had a few similar experiences, our reactions have not been the same. But then, we may not have been out for the same reasons. The only stone circle I've visited was Stonehenge and I failed to have a spiritual connection while there. Maybe it was the rain that shorted everything out. Graveyards are something else, although there are only three or four that we have visited to visit graves of relatives, including Arlington National Cemetery, where my wife's grandparents are buried and also two of my son-in-law's relatives, one of whom was only buried a week ago. It was one of his grandmothers, who actually served in the R.A.F. in WWII. Visiting cemeteries is a very sad experience for me, although I don't feel any spiritual connections. Maybe I need to go at night or something.
I have actually hiked at night in Shenandoah National Park (not nude, though). Not difficult at all if the moon is out and if the trail isn't too bad. Much of the trails I've been on there have really been green tunnels, as they have been described, but they aren't all like that.
Now, responding to MartinM's post, which has appeared this instant. I've lived in a log house with a wood-burning range in the kitchen and a coal-burning stove in the other room. The house had no bathroom and no telephone. There was electricity, though, which was a relative recent addition (this was in the early 1960s). So, I've had that experience. It was all man-made, it is true. There was a large garden that required a lot of work and wood had to be split for the stove. The place was surrounded by the woods. No one there would have understood anything you were talking about and no one went to a gym. Everyone was just about as connected with nature as they cared to be. Me, I went to college and aside from my time in the army and the jobs I did getting through school (including work on a tobacco farm), I spent the rest of my life after graduation until I retired last year working in an office polishing the seat of my pants. Yet I do not feel disconnected from nature. The warmth of a ray of sunshine is nice sometimes but this time of the year it feels better to be in the cool and shady woods. I probably have about ten good years left to enjoy all that and after that, who knows?
I think it helps to have a definite goal for an outing, be it hiking or camping, although it doesn't need to be difficult or grandiose. In fact, making the rounds of a ten-mile circle hike is a minor achievement. But I generally have a particular thing I want to accomplish on any given outing. And in planning the next trip, I usually have something in mind that I want to do differently.
Although I'm not sure if hiking nude is ever the primary object of a given hike (it probably is, though), it is usually something I intended doing. In theory, I have more flexibility, if not freedom, for trips these days but that mostly means that I don't have to worry so much about rain--not that we've had much rain lately. Anyway, the possibility of hiking nude for a while is always part of my plans, at least in warmer weather.