There are two good ways for viewing the walled Old Town of Dubrovnik from up high. The first is from the walls themselves, the second by catching the cable car up to the top of the hill above Dubrovnik.

You can walk the entire way around the Old Town of Dubrovnik on top of the fortifying walls. You pay a fee to enter and there are checks along the way as well as coffee, drink and food stops. You get all sorts of views from up there.

From the hill above Dubrovnik, you can observe some great sunset views. There is also a restaurant up there and a view into Bosnia also from the other side.