I spent the summer of 1991 in Toulouse working at LAAS on path planning for mobile robots, learning to appreciate French wines, hiking in the Pyrenees, and improving my French.
During the summer of 1992, I spent 10 weeks travelling around China, I even learned a little bit of Chinese, at least enough to bargain with the street vendors and buy "hard sleeper" tickets on the train.
In the fall of 1993, I took a trip to Turkey. We spent some time in Istanbul and went down the Mediterranean coast, exploring Ephesus and taking in a Turkish bath.
Let me know if you have any good suggestions of places to go next!