(PICTURE: An outdoor onsen.)
I've always said that my favorite thing about getting a massage in the states was the sauna/spa before the actual massage. Well, in Japan they have just that -- Onsens.
Onsens are Japanese hot spring baths. Since this country is basically sitting on top of a volcano there is a ton of naturally heated water below the surface. All over the country are these bath houses where people go for the water which is supposed to be good for your health.
Usually at the onsen there are a few set things. First, you can take a hot bath outside (like the picture). After the bath you can go into a sauna/steam room. These rooms are really hot so I have been staying in them for about five minutes max. After the sauna you're supposed to take a quick bath in FREEZING COLD water. The first onsen I went to had pretty cold water but I was able to plunge my head. The second onsen I went to had the coldest water I've ever felt. I got in up to my knees. After the cold plunge you can sit in an indoor bath with the natural hot water. If you'd like you can rinse and repeat the process.
Men and women are seperated at the onsens because everyone is butt ass naked. Yes, totally naked. I don't consider myself a shy person but this took a little getting used to...especially since I've been the only foreigner in the onsens and I've definitely gotten some stares of curiousity.