Jellyfish Lake is a small lake 460 meters (1509 feet) in length and 160 meters (525 feet) in width with a depth of 50 meters (164 feet).
The lake was formed more than 12 million years ago, as a result of a collision of two tectonic plates. The crack that was created in the earth was filled with small marine inhabitants, including jellyfish, which were able to leak through the pores in the limestone surrounding the area.
CC BY-SA 2.0 / Lukas / Jellyfish Lake on Eil Malk Island, PalauJellyfish Lake on Eil Malk Island, Palau. The Seventy Island Preserve is just visible in the upper left corner of the photograph.

Jellyfish Lake on Eil Malk Island, Palau. The Seventy Island Preserve is just visible in the upper left corner of the photograph.
© Depositphotos.com / ShalamovA female tourist snorkeling with endemic golden jellyfish in the lake at Palau. Snorkeling in Jellyfish Lake is a popular activity for tourists to Palau.

2/15
© Depositphotos.com / Shalamov
A female tourist snorkeling with endemic golden jellyfish in the lake at Palau. Snorkeling in Jellyfish Lake is a popular activity for tourists to Palau.
CC BY-SA 2.0 / Tobze / Jellyfish closeupJellyfish closeup. Only 2 species of jellyfish live in the water, gold (Mastigias papua) and lunar (Aurelia).

Jellyfish closeup. Only 2 species of jellyfish live in the water, gold (Mastigias papua) and lunar (Aurelia).
© Depositphotos.com / shalamovEndemic golden jellyfish in the lake at the Republic of Palau. Snorkeling in Jellyfish Lake is a popular tourist activity.

4/15
© Depositphotos.com / shalamov
Endemic golden jellyfish in the lake at the Republic of Palau. Snorkeling in Jellyfish Lake is a popular tourist activity.
CC BY-SA 2.0 / Albert / Jellyfish LakeA diver taking a photo in Jellyfish Lake.

A diver taking a photo in Jellyfish Lake.
CC BY-SA 2.0 / Albert / Only two species of jellyfish live in the water, gold (Mastigias papua) and lunar (Aurelia).

Only two species of jellyfish live in the water, gold (Mastigias papua) and lunar (Aurelia).
© Depositphotos.com / Ead72Millions of endemic jellyfish (Mastigias papua etpisonii) fill a marine lake in the Republic of Palau. Palau has five different marine lakes filled with different subspecies of jellyfish.

7/15
© Depositphotos.com / Ead72
Millions of endemic jellyfish (Mastigias papua etpisonii) fill a marine lake in the Republic of Palau. Palau has five different marine lakes filled with different subspecies of jellyfish.
CC BY 2.0 / James St. John / Aurelia aurita (moon jellyfish)Aurelia aurita Linnaeus, 1758 - moon jellyfish (Lake Superior Aquarium, Duluth, Minnesota, USA)

Aurelia aurita Linnaeus, 1758 - moon jellyfish (Lake Superior Aquarium, Duluth, Minnesota, USA)
CC BY 2.0 / Riza Nugraha / ChasingA diver takes a photo of a jellyfish.

A diver takes a photo of a jellyfish.
CC BY 2.0 / shankar s. / A Pacific Sea Nettle- stay away from this jellyfishA Pacific Sea Nettle is a dangerous jellyfish.

A Pacific Sea Nettle is a dangerous jellyfish.
CC BY-SA 2.0 / Tata_aka_T / A swimmer in Jellyfish Lake, PalauA swimmer in Jellyfish Lake, Palau.

A swimmer in Jellyfish Lake, Palau.
CC0 / Pixabay/Yvonnek91 / Jellyfish in the lake, Palau.

Jellyfish in the lake, Palau.
CC BY-SA 2.0 / Amanderson2 / Jelly couple with friend PalauJellyfish in the lake, Palau.

Jellyfish in the lake, Palau.
CC BY-SA 2.0 / Albert / Palau209Jellyfish in the lake, Palau.

Jellyfish in the lake, Palau.
© Depositphotos.com / ShalamovUnderwater photo of a family snorkeling with endemic golden jellyfish in the lake at Palau. Snorkeling in Jellyfish Lake is a popular tourist activity.

15/15
© Depositphotos.com / Shalamov
Underwater photo of a family snorkeling with endemic golden jellyfish in the lake at Palau. Snorkeling in Jellyfish Lake is a popular tourist activity.