Recursive islands and lakes
A recursive island or lake, also known as a nested island or lake, is an island that lies inside a lake, or vice versa.[1] For the purposes of defining recursion, small continental land masses such as Madagascar and New Zealand count as islands, while large continental land masses such as Australia do not. Islands found within lakes in these countries are often recursive islands because the lake itself is located on an island. The recursion is sometimes expressed as the order of the island, so the many islands of the earth's global ocean are zero order islands.[2]
Recursive islands
Islands in lakes

Islands in lakes on islands

These are first order islands.
There are nearly 1,000 islands in lakes on islands in Finland alone.[9]
Islands in lakes on islands in lakes
These are second order islands.
Islands in lakes on islands in lakes on islands

These are third order islands.[2]
| Name | In lake | On island | In lake | On island | Country | Area (m2) |
Coordinates | Notes |
|---|---|---|---|---|---|---|---|---|
| — | — | — | Nettilling Lake | Baffin Island | Canada | 40,000 | 66°41′15″N 70°28′48″W / 66.68750°N 70.48000°W | There are more islands in lakes on the "level 2" island in Nettling Lake. |
| — | — | — | — | Victoria Island | Canada | 16,000 | 69°47′32″N 108°14′26″W / 69.79222°N 108.24056°W | Sometimes unofficially referred to as "Inception Island", as it is a third-order island within an island.[18] |
| — | Aek Natonang (locally Sidihoni Lake[19]) | Samosir | Lake Toba | Sumatra | Indonesia | 13,125 | 2°33′52″N 98°53′0″E / 2.56444°N 98.88333°E | Two islands, the largest of which is 175 m by 75 m. |
| — | — | — | — | King William Island | Canada | 12,000 | 69°27′39″N 97°35′43″W / 69.46083°N 97.59528°W | One circular island, which is around 120m in diameter |
| — | — | Glover Island | Grand Lake | Newfoundland | Canada | 7,500 | 48°47′48″N 57°39′28″W / 48.79667°N 57.65778°W | There are several (at least seven) other, even smaller, islets in the lake |
| — | — | — | — | Baffin Island | Canada | 3,000 | 64°47′32″N 75°25′11″W / 64.79222°N 75.41972°W | One circular island, which is around 60m in diameter |
| — | — | Glover Island | Grand Lake | Newfoundland | Canada | 2,300 | 48°43′8″N 57°46′23″W / 48.71889°N 57.77306°W | In a lake 11 km south west to the lake that contains the larger island. There are no other island in this island's lake |
| — | — | — | Meelpaeg Reservoir | Newfoundland | Canada | 100 | 48°18′44″N 56°30′48″W / 48.31222°N 56.51333°W | There are 3 other smaller islands in the same lake. |
| — | Arethusa Pool | Mou Waho | Lake Wānaka | South Island | New Zealand | 225 | 44°33′15″S 169°05′3″E / 44.55417°S 169.08417°E | There are two islands in this lake, both less than 25 m across. |
| — | — | Eilean Sùbhainn | Loch Maree | Great Britain | United Kingdom | 225 | 57°41′24″N 5°29′9″W / 57.69000°N 5.48583°W | Two islets, each of which is 15m by 15m |
| — | — | — | Kooryet Lake | Banks Island (British Columbia) | Canada | ~100 | 53°21′7″N 129°59′30″W / 53.35194°N 129.99167°W | A number of small islets, the largest of which is only 10m across |
| — | — | Samosir | Lake Toba | Sumatra | Indonesia | 400 | 2°38′11″N 98°50′14″E / 2.63639°N 98.83722°E | |
| — | — | Ostrov Litvinova | Ozero Nevskoye | Sakhalin | Russia | 50 | 49°19′17″N 143°37′30″E / 49.32139°N 143.62500°E | There is (at least) one smaller island in the same lake |
| — | — | — | Jubilee Lake | Newfoundland | Canada | 20 | 48°3′50″N 55°10′24″W / 48.06389°N 55.17333°W | Several small islets, the largest of which is about 5 m across |
| — | — | Cayo pajaro | Laguna de Leche | Cuba | Cuba | 832 | 22°13′31″N 78°40′2″W / 22.22528°N 78.66722°W | There are several other islets in the lake, all about half the area of the specified islet. |
| Vulcan Point[20][21] | Main Crater Lake | Volcano Island[22] | Lake Taal | Luzon | Philippines | 1.2 | 14°00′35″N 120°59′54″E / 14.00972°N 120.99833°E | |
| — | — | — | Hatchet Lake | Adak Island | United States | 51°43′49.1″N 176°45′31.2″W / 51.730306°N 176.758667°W | ||
| — | — | — | — | Victoria Island | Canada | 944 | 71°42′16.8″N 115°25′41.4″W / 71.704667°N 115.428167°W | |
Islands in lakes on islands in lakes on islands in lakes
This is a fourth order island.
| Name | In lake | On island | In lake | On island | In lake | Country | Size (km2) | Coordinates | Notes |
|---|---|---|---|---|---|---|---|---|---|
| — | — | — | — | — | Lake Yathkyed | Canada | — | 62°39′05″N 97°47′15″W / 62.65139°N 97.78750°W | [23][24] |
Recursive lakes
Lakes on islands

Lakes on islands in lakes
These are first order lakes.
Lakes on islands in lakes on islands

These are second order lakes.
Lakes on islands in lakes on islands in lakes
There are third order lakes.
| Name | On island | In lake | On island | In lake | Country | Size (km2) | Coordinates | Notes |
|---|---|---|---|---|---|---|---|---|
| — | — | — | — | Lake Yathkyed | Canada | 0.013 | 62°39′5.8″N 97°47′11.8″W / 62.651611°N 97.786611°W | This lake itself contains an island, the most recursive island to have been discovered in the world.[24] |
See also
Notes
References
- 1 2 3 2019 Guinness World Records. August 28, 2018. pp. 40–41. ISBN 978-1-912286-43-0.
- 1 2 Dempsey, Caitlin (July 9, 2024). "Third Order Islands". Geographyrealm.com. Retrieved May 23, 2026.
- ↑ Arsene Mushagalusa Balasha; et al. (2023). "Pesticide Choice and Use Patterns Among Vegetable Farmers on Idjwi Island, Eastern Democratic Republic of Congo". SAGE Open. SAGE Publishing. Retrieved December 10, 2025.
- ↑ Wolchover, Natalie (January 24, 2012). "World's largest island in a lake on an island : Seen on Google Earth". Livescience.com.
- ↑ Québec (ministère de l'Environnement) (April 2003), "La réserve de biodiversité projetée de l'île René-Levasseur" (PDF), Bureau d'audiences publiques sur l'environnement (in French), Quebec City, p. 14, retrieved August 19, 2010
- ↑ "2019 U.S. Gazetteer Files". United States Census Bureau. Retrieved August 7, 2020.
- ↑ "Crater Lake, Oregon". NASA Earth Observatory. September 18, 2006.
- ↑ "Samosir | Location, Batak, & Facts | Britannica". Encyclopædia Britannica. Archived from the original on March 20, 2025. Retrieved December 9, 2025.
- ↑ "Suomen saaristo- ja vesistömatkailusta" (PDF). valtioneuvosto.fi / Julkaisut. Archived from the original (PDF) on January 21, 2022. Retrieved August 17, 2020.
- ↑ "Samosir Island - Everything you Need to Know about Samosir Island". Indonesia-holidays.com.
- ↑ "Colchester Town Map" (PDF). Essexhighways.org. Retrieved July 23, 2026.
- ↑ Boa Island Placenames Database of Ireland
- 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Shoreline - lakes (Ranta10), 2020. Finnish Environment Centre, ELY centres. Released under CC-BY-4.0.
- ↑ "Lac Du Chaunoy, Quebec Map". Geodata.us.
- ↑ "GNIS Detail - Ryan Island". Geonames.usgs.gov.
- ↑ "Islands within Chambers Island's Lake Mackaysee Now Protected by Door County Land Trust". Doorcountylandtrust.org. November 8, 2018.
- ↑ "Island in a Lake on an Island in a Lake on an Island". earthobservatory.nasa.gov. February 22, 2015. Retrieved March 13, 2020.
- ↑ Nadis (October 31, 2025). "In a First, AI Models Analyze Language As Well As a Human Expert =Steve". Quanta Magazine. Retrieved December 9, 2025.
- ↑ "Aek Natonang Lake – A Sub-Lake of Pangururan". Toba.indonesia-tourism.com. Retrieved August 12, 2020.
- ↑ Freedman, Andrew; Meko, Tim; Karklis, Laris (January 17, 2020). "Taal volcano's crater lake is nearly empty". Washington Post.
- ↑ "Some interesting islands and lakes". Topografisch Verbond Elbruz. Archived from the original on September 19, 2013. Retrieved February 1, 2014.
- ↑ "Volcano Island | volcano, Philippines". Encyclopedia Britannica.
- ↑ , 62°39′05″ N, 97°47′15″ W
- 1 2 "Did you know? Canada is home to the world's most 'recursive' island". Curiocity. February 25, 2022.
- ↑ "Lac Observation, Quebec, Quebec, Canada | Angler's Atlas". Anglersatlas.com.
- ↑ "Shara-Nur lake". BaikalNature Tour Operator. May 11, 1975. Retrieved March 13, 2020.
- ↑ "GNIS Detail - Lake Desor". geonames.usgs.gov. Archived from the original on April 19, 2021. Retrieved March 13, 2020.
- ↑ "GNIS Detail - Lake Richie". geonames.usgs.gov. Archived from the original on April 19, 2021. Retrieved March 13, 2020.
- ↑ Valenzuela. "Puerta laguna misteriosa [Door to mysterious lagoon]=Orlando". El Nuevo Diario (in Spanish). Archived from the original on July 8, 2020. Retrieved March 13, 2020.
- ↑ "Global Volcanism Program | Zapatera". Smithsonian Institution | Global Volcanism Program.