If you have enough money and time it seems you can go everywhere However in the world there are some places that you are forbidden to go
1.Surtsey Island reason;scientific experiments
2.Ilha de Quemida Grande Reason There are lots of poisonous snake
3.North Sentinel Island Reason The Aggression of Aborgines.
4.Gruinard Island Reason Biological weapon trial
5.Grand Shrine Japan Reason Special for the Elite Class