最早的桑拿浴很有可能是在地下山洞里。由于当时还没有掌握烟粻?技术，山洞里总是充满着火焰引起的。

Thee earliest saunas were probably underground caves heated by a fire that naturally filled with smoke as chimney making was unknown at that time.

youdao

最早的桑拿浴很有可能是在地下山洞里。由于当时还没有掌握烟粻?技术，山洞里总是充满着火焰引起的。

Thee earliest saunas were probably underground caves heated by a fire that naturally filled with smoke as chimney making was unknown at that time.

youdao