Umi Jigoku slaps you in the face with the most ridiculous shade of blue you've ever seen. The "sea hell" isn't just a hot spring; it's nature's ultimate Instagram flex, a boiling cauldron so mesmerizing you'll want to dive in, which would be your first and last mistake. The water looks like someone dumped an entire bottle of electric blue food coloring into a massive pot, bubbling with a temperature that would make a lobster cry for mercy.

But here's the kicker: this isn't just some boring hole in the ground. The surrounding gardens are a masterpiece of volcanic weirdness, with smaller orange-hued "hells" scattered about like nature's own bizarre art installation. There's even a lotus pond so surreal it could hold a toddler—not that we're recommending impromptu child-floating experiments, mind you.