3. Kish, Iran
Commonly known as Kish underground city, this secretive place was built 2500 years ago and was a water management system. Renovations have been made to transform it into a tourist attraction.
2. Cappadocia, Turkey
A famous city in this area is called Derinkuyu. It houses more than a thousand people and has shops, churches and schools. It was built for protection purposes by the Christians.
1. Burlington, Secret English City
Burlington was built for the protection of British government during nuclear war. It could support 4000 officials and had roads, railway stations and even a BBC studio. It was closed when the war ended.
Empires rise and fall. Where once underground cities had defense purposes, now they are more of tourist attractions. These cities are also looked upon with historical interest as their time passes and they become ruins.