We all know Japan is one of the more tradition-rich countries in Asia. For proof, one need look no further than the geisha culture, or how the Japanese go about entering a house. (No shoes, please; only ghosts wear them inside!)

But if you really want to soak up Japanese tradition, there might not be a better way than to visit an authentic onsen, a kind of spa that involves bathing in a hot spring, au naturel.

Onsens have been a part of the Japanese culture for ions. They’re the result of the country’s volcanic activity, are popular for their therapeutic qualities since many Japanese people believe that a good soak in a proper onsen heals aches, pains and diseases and are therefore a big driver of domestic tourism.

“In my opinion, a trip to Japan isn’t complete without a trip to an onsen,” said Hisae Komatsu, a travel specialist in Japan. “Try to make sure you book a hotel or ryokan (traditional Japanese inn) that has its own private onsen. The more traditional the better.”

So what do you most need to know before pampering yourself in a relaxing onsen soak? For starters, wash carefully beforehand and place your towel on your head while in the water.

Learn a few more key tips and you’ll be well on your way to enjoying this bathing ritual at any of the more than 3,000 onsens — including Lonely Planet’s Top 10 — that can be found throughout Japan.