Ruby, Arizona is one of the best preserved ghost towns in Arizona, but you can only gain access to it by helping in the restoration effort. It was founded as a mining camp, producing mostly copper, lead and zinc. At its peak in the mid 30s, Ruby's population reached 1,200. The population diminished after the mine was closed in the 50s. The few buildings that remain include the jail, a schoolhouse, mine offices and a handful of homes.
The Kowloon Walled City was located just outside Hong Kong, China during British rule. A former watchpost to protect the area against pirates, it was occupied by Japan during World War II and subsequently taken over by squatters after Japan’s surrender. Neither Britain nor China wanted responsibility for it, so it became its own lawless city.