Time Out says
The easiest and most popular itinerary for visitors to Dubrovnik is the stroll around its fortifications. It also should be the first, as it allows the newcomer to get their bearings and gain an appreciation of the scale of this intricate jewel, and the skill of those who designed and constructed it. You also get breathing space from the high-season masses below. This is an elevated promenade and history lesson in one. The main entrance and ticket office is by the Pile Gate – having scaled the steps, you can set your own pace, taking an hour or an entire afternoon. Dubrovnik Walks is an agency offering walking tours of the City Walls run by knowledgeable locals.