Nagaike Water Park, also known as Yamanakako Shinsui Park, is situated on the northern shore of Lake Yamanaka, the largest of the Fuji Five Lakes by area. Located in the Minamitsuru District of Yamanashi Prefecture, this waterfront park extends along the lakeside at approximately 1,000 meters elevation, providing visitors with stunning views of Mount Fuji across the water. The park serves as one of the premier viewing locations for Japan's iconic peak, positioned to capture the mountain's complete silhouette reflected in the calm lake waters.
The park's primary significance lies in its exceptional vantage point for photographing Mount Fuji and two rare natural phenomena. During mid-November to early February, visitors can witness the "Double Diamond Fuji" phenomenon, where the setting sun aligns perfectly with Mount Fuji, creating a reflection in the lake. The site is also renowned for capturing "Sakasa Fuji" or inverted Mount Fuji, where the mountain's mirror image appears on the lake's surface during calm weather conditions. These photographic opportunities attract large numbers of professional and amateur photographers, particularly during the Diamond Fuji viewing periods when parking lots become crowded.
Visitors to Nagaike Water Park can enjoy leisurely walks along the well-maintained boardwalk and cycling path that extends along the lakeshore. The park features gazebos and resting areas where guests can pause to admire the scenery. The park is open 24 hours a day, allowing visitors to experience sunrise, sunset, and nighttime views of Mount Fuji. The tranquil environment makes it ideal for photography, nature observation, and peaceful contemplation. Swan sightings on the lake are common, adding to the natural beauty of the setting.
The park offers free admission and provides free parking for approximately 80 vehicles. Restroom facilities are available on-site for visitor convenience. Access by car involves taking the Chuo Expressway to the Yamanakako exit, then following Route 138 toward Hirano. The park is located at 3222 Hirano, Yamanakako, Minamitsuru District, Yamanashi 401-0502. Public transportation options include taking buses from Fujikyu Highland or Gotemba Station to Yamanakako, then transferring to local buses heading to Hirano. The lakeside location makes it easily accessible as part of a Fuji Five Lakes tour circuit.
