Island in Lake on Island in Lake on Island in Lake: This Is the World’s Only 5th Order Recursive Island

We’ve already explored the world’s largest island within a lake on an island within a lake on an island, but this time, we’re looking at something even rarer: the only known fifth-order island on earth. In a far northern part of Canada, where most people will never travel, lies a lake with a strange distinction. Yathkyed Lake, located in the Kivalliq Region of Nunavut, contains the only known example of what’s called a fifth-order island. That means it’s an island in a lake on an island in a lake on an island in a lake—a setup that’s incredibly rare and, so far, hasn’t been documented anywhere else.

The lake itself is large, over 1,400 square kilometers, and part of the Kazan River system. It’s not surrounded by any towns or roads. Even in a country full of remote places, this one stands out for how isolated it is. For years, its special feature was only visible to those who spent time scanning satellite images or browsing Google Earth.

It was one of those online searches that caught the attention of Reddit user u/Obvious-Screen8706, who was working at a nearby mineral exploration camp. As he was preparing to leave the camp by helicopter, he noticed the “place” icon on the map and brought it up with the pilot. By chance, the route they were planning to take to the settlement of Baker Lake passed close by. They flew overhead at about 1,000 feet, and the geologist managed to take photos of the island structure from above. The group didn’t land, but according to the Reddit user, “the magic of the site would have been a little lost on the ground as the surrounding area is quite flat.” While the innermost island is quite small, the largest of the surrounding lakes appeared much bigger and more striking from the air than expected.

The formation follows a very specific pattern: a lake contains an island, which holds a lake, which holds another island, and so on—five levels deep. This makes the small landmass in the center a fifth-order island, the most complex known case of this geographic structure. Although other recursive landforms exist elsewhere, such as third-order islands in places like the Philippines, this is the only known example that goes five layers deep.

Yathkyed Lake has also attracted attention for other reasons. The region is rich in natural resources, including uranium and other minerals, and has seen exploration activity over the years. While some reports mention company interests in the area, ownership and access to lands and lakes in Nunavut often involve a combination of federal oversight and Indigenous rights, so the situation is more complex than private control.

The lake lies close to what is considered the geographic center of Canada, calculated based on the country’s extreme points east to west and north to south. This central point is near Baker Lake, about 200 kilometers northeast of Yathkyed, a small community that acts as a rare hub in an otherwise nearly empty landscape.

Despite its obscurity, this feature has become something of a quiet favorite among map lovers and geography fans. It’s not flashy, and you wouldn’t spot it unless you were really looking. But for those who enjoy tracing the oddities of how land and water come together, this one stands out for its sheer complexity—layer upon layer, hidden in plain sight in the Canadian tundra.

Sources: 1, 2, 3, 4, 5