The heat gets pretty unbearable in Beppu during the summer, with all the hot springs," says Sachiko Okuda, a veteran tour guide and native of Japan's "hot spring capital."
Looking out the bus window on the way into town, it's easy to believe her.
Steam spews from every other building.
Beppu, in central Oita prefecture, is home to more than 2,500 onsen -- hot springs.
It's the world's second largest source of thermal spring water after Yellowstone National Park in the United States. "During Golden Week, we get around 60,000 visitors staying at our onsen resorts," Okuda explains. But we're not hot-tubbing today.
We're on our way to Beppu's so-called Eight Hells (jigoku) hot springs, where the water gushes out at temperatures as hot as 150 C.
Some also spout vermillion colored steam each "hell" is different in its own intense way.
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Umi-Jigoku (Sea Hell)
About 1,200 years ago, a volcano erupted and the cobalt-blue Umi-Jigoku sprang forth -- iron sulfate being the source of its lovely color.
Don't be lulled by its beauty, though -- the hot spring is 200 meters deep and, at 98 C, almost boiling.The steam heats a nearby greenhouse where Victoria amazonica water lilies bloom between May and November. Right by the entrance, stores sell pudding cooked in the hot spring's steam.