Tanzawa Mountains Mountains

The Tanzawa Mountains are a compact mountain range in western Kanagawa Prefecture, Japan, forming part of the highland spine west of the Tokyo metropolitan area. The range contains peaks rising above 1,600 metres and is the core of the Tanzawa-Ōyama Quasi-National Park.

The area is popular for day and multi-day hiking with a network of marked trails, mountain huts and ridge walks; the highest peak, Mount Hiru, reaches about 1,673 metres. Forested slopes and exposed ridgelines offer seasonal scenery, especially spring wildflowers and autumn foliage.

The mountains are a long-standing destination for local recreation and were brought under protected management as part of the Tanzawa-Ōyama Quasi-National Park in the mid 20th century. Traditional religious routes and small shrine sites remain on several summits.

The range lies in western Kanagawa Prefecture, inland from the Sagami Bay coast, west of central Tokyo and within easy reach of Odawara, Hadano and other regional towns. Access is typically from valley trailheads served by local roads and public transport.

• Best time to visit: Best hiking seasons are late spring and autumn when trails are clear of heavy snow and foliage is at its peak.
• Trail infrastructure: Trail infrastructure includes mountain huts and marked routes; several multi-day routes link the main ridges and summits.

What to See#

• Mount Hiru: The range’s highest named summit, rising to about 1,673 metres and forming the core of the region’s alpine hiking routes.
• Mount Ōyama: A culturally significant peak with shrine routes and shorter-day hikes that sits on the southern side of the range.
• Lake Miyagase: A reservoir and recreational area at the southern edge of the mountains that serves as a common start point for nearby trails.
• Tanzawa-Ōyama Quasi-National Park: A national park designation that covers much of the range and its foothills, used to manage hiking, forestry and conservation.

Trains run to Hakone-Yumoto or Odawara with local buses or trailhead taxis connecting to Tanzawa trailheads; travel time from central Tokyo is typically 1.5-2 hours.

• If planning multi-day hikes, reserve mountain huts in advance - weekends get busy in peak season.
• Bring a detailed map and check for bear/boar notices; mountain wildlife is present but encounters are rare.