Nippara Cave in Okutama: Cool Down in the Kanto's Largest Limestone Cave
Nippara Cave in Okutama maintains a constant temperature of around 11°C year-round, making it a natural refuge from Tokyo's summer heat. One of the largest limestone caves in the Kanto region, it stretches roughly 1,270 meters in total length with a height difference of 134 meters, and is accessible in about two hours from central Tokyo.
Highlights Inside the Cave
The public section is about 750 meters long and is walked as a one-way route in around 40 minutes. Highlights include the towering stalactite "Oshika-dora," delicate curtain-like limestone formations, and dramatic colored lighting. Some sections have wet, slippery floors and low ceilings, so sneakers or trekking shoes are essential. A light jacket is recommended given the 11°C temperature.
A Summer Retreat from the Heat
Even on days when outdoor temperatures exceed 35°C, Nippara Cave stays at a refreshingly cool 11°C — like stepping into a natural refrigerator. Cold air flows from the entrance, and the 40-minute tour provides a quick, welcome escape from summer heat. It is an ideal stop for anyone visiting the Okutama area in summer.
Combining with Other Okutama Spots
The wider Okutama area offers canoeing and SUP at Shiromaru Lake, rafting on the upper Tama River, and lakeside walks at Okutama Lake. Campgrounds such as Yama no Furusato Mura and Hikawa Campground make it easy to extend the trip into a one- or two-night stay under a starry sky.
Getting There and Admission
Take the JR Ome Line to Okutama Station, then a Nishi Tokyo Bus to either the Higashi-Nippara or Nippara Shonyudo stop, followed by a 20–25 minute walk. Check the bus schedule in advance. Admission is ¥900 for adults, ¥600 for junior high students, and ¥300 for elementary students. Parking is limited, so public transportation is advised.
Experience Okutama's Natural Scale This Summer
Nippara Cave offers a sensory experience far removed from urban life — the cold air and the sound of flowing water as you step inside create an atmosphere the city cannot replicate. This summer, a trip to Okutama and Nippara Cave is an opportunity to feel the full, quiet power of nature.