I’ve heard that Bhaktapur which is about 9 miles from Kathmandu is worth a Visit, and also Mustang which is supposed to be a living time capsule.

Hey, stop by your local STA Travel branch. While you are there, look at the tours offered to Nepal. I am a huge fan of tours. But, even if all you are looking for is information, the tours offer itineraries that would give you a really good idea of the locations and activities in Nepal.