Surrounded by lush forest on all sides and untouched by human civilization, the heart-shaped Lake Toyoni is a hidden gem among Japan’s many tourism attractions.

Up until a few years ago, Lake Toyoni was virtually unknown to most Japanese, but a popular television commercial featuring an aerial view of the heart-shaped natural wonder turned it into a popular tourist spot virtually overnight. The internet is full of digitally-altered heart-shaped lakes, but Toyoni is one of the few, if not the only one, in the world that actually has this shape, so when people learned that it was real, they flocked to the island of Hokkaido to see the natural wonder for themselves.

Originally known as Kamuito, or, “A Marsh Where a God Lives”, the 30-hectare emerald lake was eventually given its current name in honor of the nearby Mt. Toyonidake. Nowadays, most people know it as “Heart Lake”, because of its unique shape.

Seeing Lake Toyoni from the air is always a breathtaking experience, but the best time to enjoy the stunning aerial view is in mid-autumn, when the green forest surrounding it changes to various hues of red and brown. A local company operates a helicopter tour over the lake in the month of October.

While taking to the air is the most popular way of experiencing Japan’s heart-shaped lake, some people prefer the serenity of its shores. To reach its peaceful, emerald waters, tourists have to trek to a deep forest, part of a wildlife sanctuary.

For more stunning natural wonders, check out Tuscany’s unique limestone pools, and Russia’s Big Stone River.