Went to a camping in the Laurentians in Québec (Ste-Agathe) and there were those things near some camp sites. The sites are only accessible by footpaths. No car access. And if you bring a bike, you have to walk it up a hill, so I doubt they are bike racks.
I’m surprised that no one has said “concrete anchor for an unfinished building structure”. Doesn’t this look like someone laid the foundation for a tower or building or something with the concrete anchor underground, and this is a tie-in area for the additional rebar structure of either a column or a wall that could have joined here? The metal configuration here looks a lot like what’s inside concrete pillars but we usually don’t see it