Keio Takaosan Onsen Gokurakuyu

Keio Takaosan Onsen Gokurakuyu is a day-trip hot spring facility located in Takao-machi, Hachioji, Tokyo, directly adjacent to the ticket gates of Takaosanguchi Station on the Keio Takao Line. Opened on October 27, 2015, it was the Keio Group's first hot spring facility, developed in partnership with the Gokurakuyu bathhouse chain. Drilling for the spring began in October 2012, and the operator struck its own source at a depth of roughly 1,000 meters, giving the facility instant appeal thanks to its location right at the trailhead of Mount Takao.

The water is classified as an alkaline simple hot spring with a notably high pH of 9.9. The source temperature is 26.2 degrees Celsius, with a flow rate of 300 liters per minute, and the water is faintly white, clear, tasteless, and carries a faint sulfurous scent. The open-air rock bath that uses the genuine hot spring water is heated but neither diluted nor circulated, preserving the source water's silky, smooth texture, which has earned it a reputation as a bath for beautiful skin.

Indoor baths include a silk bath with microbubbles, a rotating seasonal bath, a sauna, a sitting bath, and a cold plunge bath, while the outdoor area offers a natural hot spring rock bath (in both lukewarm and hot variations) plus a rare artificial carbonated stone bath. The facility also has a restaurant, a nap lounge, private paid tatami rooms, and massage and body care services. It is open from 8:00 to 22:30 (last entry 21:45) year-round with no closed days. Admission is 1,100 yen for adults and 550 yen for children on weekdays, rising to 1,300 yen and 650 yen on weekends, holidays, and peak seasons (free for children age 3 and under).