Area around the world wonders
It won’t be possible to relocate there, only settle. The mist will stay until the end of the game round to indicate this restriction.
Size 13² map tiles = a quadrat with a radius of 7 fields around the World Wonder tile.
This is fine, but it won't resolve all the problems. Some players still will be able to be menhired near a treasury or a hammer to destroy it and come back. In contrast to WW there is usually less than 30k stationary defence, so average 30k club hammer and 6k catapults would be enough to demolish a target.
In my opinion there are several much better ways to prevent such situations:
1) Every player can have a personal timer like begginer's protection. Usually average player already has 3-4 villages in a month of playing, so situations when someont would like to be menhired in a month of playing are very rare.
2) Every player can have a troop limit like 10-15k crop consumption and if he has more troops then he won't be able to be menhired.
3) Every player can have a timer after being menhired that will forbid to attack other players. Actually the duration may depent on player's troop count. For example <10k troops - 12h, 10-20k - 24h, >20k - 48h. It'll be enough to organize defence and destroy granaries in the menhired village, so starvation will seriously reduce that hammer and make it not dangerous.
Maybe such options has some disadvantagies, but I'm sure it would be a smaller problem than abusing that game mechanic.