Kameiwa Cave
When the timing is just right, glimpse a heart-shaped vision created by sunlight at this magical cave.
Twice yearly around the equinoxes, morning rays of sunlight flow through Kameiwa Cave and reflect on the water in front of it to form an image of a gleaming heart.
This magical event occurs at Noumizo Waterfall, located within Shimizu Keiryu Park in Kimitsu City. This area is not all that far from Tokyo, being located on Chiba Prefecture’s rustic Boso Peninsula—one of our Top 10 Japan Travel Destinations for 2019. Featured on National Geographic, Kameiwa Cave (which means Turtle Rock Cave), formerly a relatively unknown site, gained notoriety for hosting one of the most whimsical sights in all of Japan.
Japan’s most Instagrammable cave
The cave — which is more of an arch embracing a cascading waterfall — gained fame when an Instagram photo of the heart-shaped spectacle went viral in 2015. Since then, it’s become a popular tourist attraction. Coming from the land of Studio Ghibli, it’s been appropriately compared to something out of an anime or a fairytale. Though the cave appears to be a glorious natural wonder, its origins are man-made. It was likely constructed in the 1600s as an irrigation tunnel to water nearby rice fields.
The best time to catch a glimpse — and a photo sure to get scores if not hundreds of likes — of the mystical heart is on spring and fall mornings (around the equinox) between 6 and 8 a.m.
Don’t worry if you can’t make it on one of the equinoxes, however. During the spring and summer, lush green surrounds the rocky arch and fireflies come out at night to dance above the water. In autumn, verdant transforms into crimson wreathing the cave in vibrant colors. It’s truly a worthwhile sight year-round and has other attractions to see, too.
Oyama Senmaida
There’s a lot more to love about Kameiwa Cave aside from its photogenic phenomena.
The surrounding area matches the cave in beauty. Chiba Prefecture’s Boso Peninsula, where you can find Kameiwa and Shimizu Keiryu Park, is brimming with attractions. A mountain temple with a large stone Buddha carved straight into the jagged rock face looms over the area. The famous Oyama Senmaida, gorgeous terraced rice fields, is a modern-day reminder of the area’s farming heritage. From the peninsula’s southern tip, you can even see as far as Mount Fuji on clear days.
Located just east of Tokyo across scenic Tokyo Bay, the Boso Peninsula is easily accessible from the capital by train, bus, or car. It’s also convenient to Narita International Airport.