Zenkoji Temple is located in Nagano, Japan. The Buddhist temple was built in in the 1700s, and contains various Buddhist statues. Visitors are required to pay a fee when entering the hall's inner chamber, enabling them to take a closer look at the main altar. There is also an underground passage, that visitors are able to walk through in absolute darkness, with the hopes of finding the "key to paradise". The key is attached to a wall along the passage and Buddhists believe that those who touch it, will be granted salvation.