You can land anywhere but be very fast. If you are hovering over the town then you will be breaking the 300m aviation rule. Also don't land in the road because people will probably crash into it. Btw, in kavala you can land on the beach. In regards to the laws, only land on designated areas such as the beach otherwise your heli may be scrapped.
Just remember to ask police for permission via the police request on the phone if you want to land within a town. Outside of towns and landing normally there isn't an issue from police