Another good option if you're not interested in hiking is bicycle touring. A few years ago I spent a summer cycling across France, Germany, Switzerland, and Austria and it was an absolutely incredible experience. After cycling for roughly 6 hours per day over six weeks, I lost a ton of weight, despite eating anything and everything I wanted. (Which was more food than I would normally eat at home, considering you're burning thousands of calories per day in exercise alone.) Definitely would recommend to anyone interested in combining long, sustained periods of exercise with traveling.