Gateways to the past
Even though they are hundreds and, in some cases, thousands, of years old, many ancient walls still stand across the globe. Some of these structures, such as Hadrian's Wall (pictured), are popular tourist attractions, while others are crumbling, mostly forgotten relics that give history buffs a chance to come face-to-face with the past. There are even a few instances where ancient walls have survived urbanization and now stand amidst malls and skyscrapers as a reminder of a city's ancient roots.
Except for a few famous examples, these structures are often overshadowed by historic castles or artifact-filled museums. But they really are living parts of the past, providing a chance to experience the ancient world outside of a sterile exhibit space.