Lengshuikeng Public Baths are a simple, local way to soak in Yangmingshan's hot-spring country without booking a spa hotel. The baths are segregated by gender and used nude, with a small 40°C pool and strict washing rules before you get in.
Bring your own soap and towel, and expect a very plain public-bath setup. The appeal is the mountain setting and the everyday ritual, not luxury.