Forum:Ending of Return of the King

So i hvae just watched all three movies and have a few questions hopefully someone here can help me!

At the end of the moive where exactly does the ship go to and why must Frodo go as well, if Frodo didnt HAVE TO take the ring then y must he leave? Sure he went through a whole heap and going back to normal life in the shire would be hard is this the reason why??

Thanks