Yes. Anything you can do that involves moving around (such a walking) will increase your metabolism and help you burn more calories. Walking is great for beginners, overweight people, those who have medical conditions that prevent them from any other type of activity and in general for those who just love to go for a walk outdoors (or even at indoor places such as malls). Controlling the calories you take in is also another good way of making sure walking will be more effective.
Choosing areas where the grade of elevation of the path changes (increases or decreases) and also the choice of the landscape (walking on sand or grass will increase the intensity and help you burn more calories) are factors that influence the amount of calories you will burn during your walk. Also adding extra weight on you (wearing a backpack or carrying a sandbag or even some free weights or kettlebells) will add some extra intensity to your walk and make you burn more calories.