My girlfriend and I spent a short time in Guatemala and absolutely loved it. We explored cathedrals, museums, and gigantic markets. We took a hike up active Pacaya volcano. We lounged around Lake Atitlan and watched movies in the coffee shops when it was cold and rainy. We went on a zipline canopy tour. We went to a football game. We discussed the politics of the Guatemalan civil war with Spanish students. And we ate lots of wonderful food.
Everyone should go, it's got something for everyone. Even beaches (edited).