Recursive islands and lakes

A recursive island or lake, also known as a nested island or lake, is an island or a lake that lies within a lake or an island.
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.

Recursive islands

Islands in lakes

Island	In lake	Country	Area	Coordinates	Notes
Manitoulin Island	Lake Michigan–Huron	Canada	2,766		Largest lake island in the world
René-Levasseur Island	Manicouagan Reservoir	Canada	2,020		The island is artificial as the lake it is in was made by flooding a smaller existing lake due to the creation of the Daniel-Johnson dam.
Soisalo	spread across several lakes	Finland	1,638		The largest island in continental Finland. It has shores to four different lakes, but they are not all at the same level.
Sääminginsalo	Saimaa	Finland	1,090		Separated from one side by an artificial canal.
Olkhon Island	Lake Baikal	Russia	730
Isle Royale	Lake Superior	United States	535
Ukerewe Island	Lake Victoria	Tanzania	530
St. Joseph Island	Lake Michigan–Huron	Canada	365
Drummond Island	Lake Michigan–Huron	United States	347
Idjwi	Lake Kivu	DR Congo	340
Kotasaari	Kallavesi	Finland	285		Separated from one side by an artificial canal.
Ometepe	Lake Nicaragua	Nicaragua	276		Made of two conjoined volcanic islands
Zapatera	Lake Nicaragua	Nicaragua	54
Big Island	Lake of the Woods	Canada	~200
Mercer Island	Lake Washington	United States	33.4		Crossed by the Lacey V. Murrow Memorial Bridge, the second longest floating bridge in the world.
Duck Island	Green Lake	United States
Wizard Island	Crater Lake	United States	1.3		Crater Lake itself is a caldera formed by the eruption of Mount Mazama; a series of smaller eruptions later formed cinder cones on the caldera floor, of which Wizard Island is the highest, and the only one now visible above the lake's surface.
—	Orba Co	China			Highest-elevation islands in the world. There are three islands of quite similar size.
Silcox Island	American Lake	United States			There are residents that live on this island, there is no ferry service to them.
Preble Island	Great Slave Lake	Canada			A large recursive island with zero people living on it.

Islands in lakes on islands

There are nearly 1,000 islands in lakes on islands in Finland alone.

Name	In lake	On island	Country	Area	Coordinates	Notes
Samosir	Lake Toba	Sumatra	Indonesia	630		Largest island in a lake on an island. Manmade from digging canal
Gatter Island	Lake Hazen	Ellesmere Island	Canada	0.2
Glover Island	Grand Lake	Newfoundland	Canada	178		Largest naturally occurring island in a lake on an island.
Motutaiko Island	Lake Taupō	North Island	New Zealand	0.11
Goodin Island	Lake Campbell	Fidalgo Island	United States	0.09
Mokoia Island	Lake Rotorua	North Island	New Zealand	1.35
Rahui Island	Lake Waikareiti	North Island	New Zealand			Largest of several islets in Lake Waikareiti
Mou Waho	Lake Wanaka	South Island	New Zealand	1.2		Largest of several islets in Lake Wanaka, including Stevensons Island
Pigeon Island	Lake Wakatipu	South Island	New Zealand	1.7		Largest of several islets in Lake Wakatipu, including Pig Island / Mātau and Hidden Island
Pomona Island	Lake Manapouri	South Island	New Zealand	2.6		Largest of several islets in Lake Manapouri; largest lake island in New Zealand
Motmot Island	Lake Wisdom	Long Island	Papua New Guinea	0.04
—	West Lake	Brownsea Island	United Kingdom	0.0008
Belle Isle	Windermere	Great Britain	United Kingdom	0.17
Storgrynnan	Vandöfjärden	Fasta Åland	Finland	0.12
—	Senanayaka Samudra	Sri Lanka	Sri Lanka	0.02
Derrywarragh Island	Lough Neagh	Ireland	United Kingdom	0.56
Boa Island	Lower Lough Erne	Ireland	United Kingdom	5.3		Largest lake island of the United Kingdom and inland island of Ireland
Sveta Marija	Veliko jezero	Mljet	Croatia	0.017
Chikubu Island	Lake Biwa	Honshu	Japan	0.14
Takeshima	Lake Biwa	Honshu	Japan	0.6
Okishima	Lake Biwa	Honshu	Japan	1.51		Largest of the three islands located within Lake Biwa, which is Japan's largest lake.
Nakajima (Lake Kussharo)	Lake Kussharo	Hokkaido	Japan	5.81		Largest recursive island in Japan
Nakajima (Lake Toya)	Lake Tōya	Hokkaido	Japan	4.84
Takeshima	Lake Biwa	Honshu	Japan	0.6
Okinajima	Lake Inawashiro	Honshu	Japan	0.07
Loeha Island	Lake Towuti	Sulawesi	Indonesia	12.5
Lalu Island	Sun Moon Lake	Nantou	Taiwan	0.882
Yufei Island	Qingcao Lake	Hsinchu	Taiwan	0.00425
—	Kasegalik Lake	Flaherty Island	Canada			There are several other islands in that lake.
Isla Cabritos	Lago Enriquillo	Hispaniola	Dominican Republic	16.67
—	—	Cat Ba Island	Vietnam	0.0005		There is a smaller one, right at the south of it.
—	Blöndulón	Iceland	Iceland			There are nine other islands in this lake, all significantly smaller than this one.
—	—	Great Britain	United Kingdom	0.14		Occasionally referred to as "Castle Park Island"

Islands in lakes on islands in lakes on islands

Name	In lake	On island	In lake	On island	Country	Area	Coordinates	Notes
—	—	—	Nettilling Lake	Baffin Island	Canada	40,000		There are more islands in lakes on the "level 2" island in Nettling Lake.
—	—	—	—	Victoria Island	Canada	16,000		Sometimes unofficially referred to as "Inception Island", as it is a third-order island within an island.
—	Aek Natonang	Samosir	Lake Toba	Sumatra	Indonesia	13,125		Two islands, the largest of which is 175 m by 75 m.
—	—	—	—	King William Island	Canada	12,000		One circular island, which is around 120m in diameter
—	—	Glover Island	Grand Lake	Newfoundland	Canada	7,500		There are several other, even smaller, islets in the lake
—	—	—	—	Baffin Island	Canada	3,000		One circular island, which is around 60m in diameter
—	—	Glover Island	Grand Lake	Newfoundland	Canada	2,300		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		There are 3 other smaller islands in the same lake.
—	Arethusa Pool	Mou Waho	Lake Wānaka	South Island	New Zealand	225		There are two islands in this lake, both less than 25 m across.
—	—	Eilean Sùbhainn	Loch Maree	Great Britain	United Kingdom	225		Two islets, each of which is 15m by 15m
—	—	—	Kooryet Lake	Banks Island (British Columbia)	Canada	~100		A number of small islets, the largest of which is only 10m across
—	—	Samosir	Lake Toba	Sumatra	Indonesia	400		-
—	—	Ostrov Litvinova	Ozero Nevskoye	Sakhalin	Russia	50		There is one smaller island in the same lake
—	—	—	Jubilee Lake	Newfoundland	Canada	20		Several small islets, the largest of which is about 5 m across
—	—	Cayo pajaro	Laguna de Leche	Cuba	Cuba	832		There are several other islets in the lake, all about half the area of the specified islet.
Vulcan Point	Main Crater Lake	Volcano Island	Lake Taal	Luzon	Philippines
—	—	—	Hatchet Lake	Adak Island	United States
—	—	—	—	Victoria Island	Canada	944

Recursive lakes

Lakes on islands

Name	On island	Country	Size	Coordinates	Notes
Nettilling Lake	Baffin Island	Canada	5,542	66°29′N 70°20′W
Lake Alaotra	Madagascar	Madagascar	900	17.5°S 48.5°E
Laguna de Leche	Cuba	Cuba	67.2
Lough Neagh	Island of Ireland	Northern Ireland/United Kingdom	392
Lough Corrib	Island of Ireland	Republic of Ireland	176	53°26′N 9°14′W
Loch Lomond	Great Britain	Scotland/United Kingdom	71	56°05′N 4°34′W
Lake Kawaguchi	Honshu	Japan	6.13		The largest among the Fuji Five Lakes
Þingvallavatn	Iceland	Iceland	84	64°11′N 21°09′W
Lake Taupō	North Island	New Zealand	616
Lake Wakatipu	South Island	New Zealand	289
Lake Biwa	Honshu	Japan	670	35°20′N 136°10′E	Largest lake in Japan
Lake Toba	Sumatra	Indonesia	1130
Lake Ranau	Sumatra	Indonesia	126
Lake Singkarak	Sumatra	Indonesia	108
Lake Towuti	Sulawesi	Indonesia	561
Lake Poso	Sulawesi	Indonesia	323
Lake Matano	Sulawesi	Indonesia	164

Lakes on islands in lakes

Name	On island	In lake	Country	Size	Coordinates	Notes
Lake Manitou	Manitoulin Island	Lake Michigan–Huron	Canada	106		-
Lac Observation	René-Levasseur Island	Manicouagan Reservoir	Canada	13.5
Ylä-Enonvesi	Sääminginsalo	Saimaa	Finland	12		Includes Lake Saarijärvi that forms its southern part. Separated by an artificial canal, Sääminginsalo might not be considered an island.
Kulkemus	Partalansaari	Pihlajavesi (Saimaa)	Finland	5.8
Saajuu-Palovesi	Partalansaari	Pihlajavesi (Saimaa)	Finland	4.1
Saravesi	Kotasaari	Kallavesi	Finland	4.1		Separated by an artificial canal, Kotasaari might not be considered an island.
Oininki	Äitsaari	Saimaa	Finland	2.6
Malosenjärvi	Viljakansaari	Pihlajavesi (Saimaa)	Finland	1.4
Valkiajärvi	Hurissalo	Saimaa	Finland	1.4
Ruokojärvi	Partalansaari	Pihlajavesi (Saimaa)	Finland	1.3
Närtejärvi	Viljakansaari	Pihlajavesi (Saimaa)	Finland	1.2
Kylliönjärvi	Viljakansaari	Pihlajavesi (Saimaa)	Finland	1.1
Lapinjärvi	Hurissalo	Saimaa	Finland	1.1
Shara-Nur	Olkhon Island	Lake Baikal	Russia
Siskiwit Lake	Isle Royale	Lake Superior	United States	16.8
Lake Desor	Isle Royale	Lake Superior	United States
Lake Richie	Isle Royale	Lake Superior	United States
Lake Mindemoya	Manitoulin Island	Lake Michigan–Huron	Canada	38.7
Lake Kagawong	Manitoulin Island	Lake Michigan–Huron	Canada	55.6
Little Lake	Washington Island	Lake Michigan	United States	0.17
Lake Windigo	Star Island	Cass Lake (Minnesota)	United States	0.8
Fox Lagoon	Pelee island	Lake Erie	Canada	0.02
Lake Henry	Pelee island	Lake Erie	Canada	0.345
Laguna del Volcan Maderas	Ometepe	Lake Nicaragua	Nicaragua	0.034
Laguna de Zapatera	Zapatera	Lake Nicaragua	Nicaragua	0.19
Antoniyevskoye Lake	Valaam	Lake Ladoga	Russia	0.028
Ozero Leshchevo	Valaam	Lake Ladoga	Russia	0.27
Lake Geneserath	Beaver Island	Lake Michigan–Huron	United States	2
Ösjön	Ammerön	Revsundssjön	Sweden	0.58
Igelviken	Färingsö	Mälaren	Sweden	0.47
Ändsjön	Frösön	Storsjön	Sweden	0.32
Gråtjønna	Røssvassholmen	Røssvatnet	Norway	0.05
—	—	Lake Chad	Cameroon			There is another, smaller lake on that island. There are a few more islands in Lake Chad that have a lake on them.
Süvähaud	Piirissaar	Peipus	Estonia
—	—	Thac Ba Reservoir	Vietnam	0.05		There are some extremely tiny islets in that lake.

Lakes on islands in lakes on islands

Name	On island	In lake	On island	Country	Size	Coordinates	Notes
—	—	Nettilling Lake	Baffin Island	Canada	1.55
—	Glover Island	Grand Lake	Newfoundland	Canada	1.40
Arethusa Pool	Mou Waho	Lake Wānaka	South Island	New Zealand	0.05		-
—	Rahui Island	Lake Waikareiti	North Island	New Zealand	0.003		-
—	—	Jubilee Lake	Newfoundland	Canada	0.025		-
—	—	Mölnorträsk	Fårö	Sweden	0.00006		Extremely small
—	—	—	Baffin Island	Canada			-
Molemole	Motu'a'ali	Motu Si'i	Niuafo'ou	Tonga	0.02
—	Sandey	Þingvallavatn	Iceland	Iceland
—	Gatter Lake	Lake Hazen	Ellesmere Island	Canada			Northernmost lake of its kind in the world.
—	Teinholmen	Vestrevatnet	Osterøy	Norway