Isn't Dubrovnik beautiful and intriguing? Views like this abound, but you'll miss a lot during your visit if you don't understand why the city developed as it did and some of the challenges it has faced in recent years.
A walking tour in several languages can be be booked here, but Dubrovnik is typical of many tourist destinations in that there are other options, too. If you'd like to take the 1.3-mile walk around the old city walls, it's possible to purchase an audio tour with marked stopping points along the way for a modest price. Taxi drivers will also offer to take you on a short drive through the immediate area for a fee that you'll want to negotiate carefully before getting inside the vehicle.
The point is there are plenty of ways to experience such a destination without booking a traditional (and perhaps expensive) walking tour.