Happyland

Happyland is a pocket dimension of unknown size. All of the currently explored areas of this pocket dimension are inhabited by a decaying theme park which appear to have once presented a facade of a family friendly location but holds sinister, twisted secrets.

History
A portal to Happyland was discovered in Hiroshima in 1945 soon after the atomic bombing. It is believed that the atomic bombing may have caused the portal to open. A scientific facility was built around the portal by the United States, who sent a group of criminals through the portal. The group spend several hours exploring and returned minus 3, whom had vanished. Soon after a group of 21 American soldiers were sent to explore the pocket dimension and learn clues as to the disappearance of the 3 from the previous group. Only 4 soldiers returned, one of whom was somehow blinded in the pocket dimension, one missing his arms, one unable to speak, and one whose skin began to decay over the following months.

Further exploration revealed the presence of mysterious shadowy figures who were occasionally seen standing in high places. No attempts to communicate with the shadowy figures have succeeded.