That only talks about being able to travel from one country to another within the EU. Not that any country can't restrict movement within one area in it's borders.
I'm sure you can't freely wander onto a military base in any EU country and claim it's your right of free movement to go anywhere you want.
Yes but on the other extreme if a state in the EU tried to create a 1 acre free movement zone within the country and then restricted movement everywhere else they would run afoul of the law. It's not black and white.
The question is where restricting access to an entire city lives.
The question is what constitutes restriction. They aren't telling anybody they can't go there at all, just that they have to make a reservation and pay a fee. Likewise you can travel into any EU country, but that doesn't mean they can't require you to show a passport.
well there are such things as gated communities, where only residents are allowed through the gate. it's not difficult to imagine this being extended to a kind of special-economic-zone where only members are allowed. in fact I believe that's a plot point in snow crash.
https://www.europarl.europa.eu/factsheets/en/sheet/147/free-...