On a cold, rainy day I was soaking, ocean-side, in a hot spring fed pool. Hawks circled overhead, ocean waves lapped at the rocks below; it was heaven.
Enospa, on the island of Enoshima, is less than an hour outside of Tokyo, but it feels worlds away. An upscale complex filled with different types of hot spring pools, it is a great 'ladies only' or 'couples' get-away. Although popular with teens, children cannot really play in the water, so it may not be the best choice for families with small kids. The pools are indoors, outdoors, and a few are even in grotto-like caves opening to the sea. There are also saunas and whirlpools. Everything is co-ed and bathing suits are mandatory; except in segregated traditional Japanese style baths connected to the locker rooms.
On the fourth floor is the Beng Teng Spa, a lovely Southeast Asian themed spa. On the second floor there is a medically-based spa that focuses on Japanese-style massage.
Visiting Enospa can be a whole day experience. Between soaks in the pools and spa treatments, I recommend visiting the fourth floor Italian restaurant for lunch. With seats along the window, there are beautiful views of the Shonan coastline. If it is clear, you can even see Mt. Fuji.
When entering Enospa, visitors take off their shoes and put them in a locker. The key is removed from the locker and is taken to the front desk and it becomes a ‘charge card’ for the day. Everything purchased, including the entrance fee, is charged to the wristband. The total is paid when leaving.
At the front desk they will ask if anyone has tattoos or if anyone has been drinking a lot of alcohol (either case will be denied entry). They will also give you a mesh bag containing a small towel, large towel, and a robe. If you hope to get a spa treatment, I recommend going to the spa desk first to make a reservation (or call ahead of time).
If you don't want to do an entire day at Enospa, spend some time exploring the island itself. Or, the Enoshima Aquarium is within walking distance, and so is the Enoden (a streetcar that will take you to Kamakura).