The Wizards' Tower
The tower is located in Westhelm Woods, which is a separate map located in northwestern Westhelm.
Once inside Westhelm Woods, you will have to do a small puzzle involving a nefarious Ghost who likes to mess with players. Simply listen to the Ghost's hints and obey any orders he gives - the Ghost will never lie to you.
Alternatively, the path needed to navigate through Westhelm Woods to the Wizards' Tower is Down, Left, Right, Up, Up.
After arriving at the Wizards' Tower, you will be able to join the Mages' Guild, if you are a Mage. Otherwise, you can still collect an amount of starter gold from talking to the door lady.