I was excited about visiting Dubrovnik because it's a UNESCO World Heritage Site, and I wanted to take panoramic shots of the city to rival the ones I had seen on the Internet that lured me to Croatia in the first place. So I was eager to walk the walls, camera in hand.
On our first day in Dubrovnik, however, I hesitated to spend the money (about $15) to gain access to the top of the city walls because it looked like a tourist nightmare. You can only walk in one direction, and it's difficult to stop because you'll probably create a traffic jam and people behind you cannot easily pass. I'm a little claustrophobic in those situations, but I wanted my panoramic photos. So I waited until the following morning, before the cruise ships docked, and I'm so glad that I did. The vantage point from the top of the wall is fabulous, and you can sneak a peek at the daily lives of the residents as you walk by apartments and schools. My best photos of the city were taken from the wall. And who can argue with this view of the Adriatic?
My advice: Go as early in the day as possible. Take your time walking around the city's perimeter. Pretend you're a guard in medieval Dubrovnik and scan the Adriatic for marauding vessels. When you see the cruise ships approaching and the people disembarking, come down and enjoy coffee and breakfast and leave the walls to the tourist mobs.
You can see more of my Dubrovnik images here: http://weirdandcoolstuff.wordpress.com/tag/dubrovnik/