The Tunnels of the Ningyo were a cluster of strange caves and circular tunnels beneath Kaigen’s Island. Mostly they proved dangerous for explorers on the island, due to pitfalls, collapsing roofs and toxic air. Most troublesome was some evidence of the taint, believed to be remnants of the Dark Wave. 
When first discovered the structure of the tunnels were thought to be artificially created, some thought by the aquatic Ningyo. Later wintess accounts of the forming of new rock from the Fire Fountains however, indicated the tunnels could simply be a result of the natural interation of earth, fire and water kami.
Most tunnels were less than a hundred feet long, containing little of interest. Some, about one in ten, extended for many hundred feet. Diameters ranged from as little as two feet to ten feet. Most were straight, sloping gradually towards the island's margins, although some were known to drop sharply.
Most tunnels were empty, although the occasionally items lost overboard or shipwrecks could be found. One such find was of a "Living Cannon" which had been used by the tainted Black Wave fleet. Another tunnel was the home to vicious aquatic troll-like creatures. In addition to these threats, potential pitfalls, cave-ins and jets of scalding steam were a constant hazard to any exploration.
|This Mantis Clan related article is a stub. That means that it has been started, but is incomplete. You can help by adding to the information here.|