Pokemon GO players have been caught in some curious situations in their eagerness to complete their collections, but for the most part, people tend to just hover around places they already know.
For the adventurous types, however, the game presents an opportunity to go exploring. While it' perfectly fine to explore an area or neighborhood that you aren't exactly familiar with, there are some places that should be left alone, whether they contain a Charizard or not.
The same rules apply to Pokemon Gyms, and while it is quite difficult sometimes to resist an unoccupied Gym, some are better left alone.These places aren't in the realm of more common locations like cemeteries, memorials, and churches either. The ones represented here can actually be quite dangerous, and if your Pokemon hunting pride is set aside for a minute, you'll understand why (via Asia One).
The first location is based in Australia, specifically the wreckage of the SS Alkimos. Now this appears to be a Pokestop as opposed to a Gym, but the same theory is in play. The ship sank underwater in 1963, and while I'm sure there are a few Pokemon to be had in the area, it isn't worth getting yourself stuck down there to find out.
Next up is a Gym located in Oraimachi, Ibaraki Prefecture in Japan. This Gym is linked one of the Tori gates that surround the Oarai Isosaki Shrine, and it sits on the edge of some scattered rock formations. Getting to it would be difficult enough, but staying near is actually worse, as the gate is constantly hit by crashing ocean waves, so even if you get there and start to take on the Gym's guardian, you could be swept right off and into the steep current.
The final Gym is located right in the heart of the demilitarized zone that resides between North and South Korea. It was discovered by a member of the South Korean Military, and as of yet, the Gym hasn't been claimed. With tensions as high as they are between the two territories, and land mines laying about to be mindful of, there is no Pokemon worth that much risk.