The largest island in the world is Greenland.
Greenland is an autonomous country within the Kingdom of Denmark. It is located between the Arctic and Atlantic Oceans, and east of the Canadian Arctic Archipelago.
Greenland is, in terms of its area, the world's largest island. Over three-quarters of Greenland is covered by the largest ice sheet in the world, except for that of Antarctica. It has a population of 56,370 (in 2013), and is therefore the least densely populated country in the world. The capital of Greenland is Nuuk.
The largest island in a lake is Manitoulin Island.
Manitoulin Island is a Canadian island located in Lake Huron, in the province of Ontario, and is the largest island in a lake the world at 1,068 square miles and a population of 12,600 peoplr. This island has been inhabited by various peoples since 10,000 BC.
The largest island in a river is Ilha do Bananal.
Bananal Island is an island formed from the bisection of the Araguaia River, in southwestern Tocantins, Brazil. It is the largest "fluvial" island in the world, at 217 miles long and 34 miles wide. Its total area is 7,400 square miles, twice the size of Lebanon or Jamaica.
The largest island in fresh water is Marajó.
Marajó is an island located at the mouth of the Amazon River in Brazil. It is part of the state of Pará. With a land area of 15,500 sq mi, which compares in size to Switzerland, it is a large coastal island almost completely surrounded by fresh water. Its northeast coastline faces the Atlantic Ocean. The island sits almost directly on the equator. Together with smaller neighboring islands, separated from Marajó by rivers, it forms the Marajó Archipelago.
The largest man-made island on an island is Samosir.
Samosir is a large volcanic island in Lake Toba, located in the north of the island of Sumatra in Indonesia. The lake and island were formed after the eruption of a supervolcano some 75,000 years ago. The island was originally connected to the surrounding caldera wall by a small isthmus, which was cut through to aid navigation.
At 247 sq mi, Samosir is the largest island within an island, and the fifth largest lake island in the world. It also contains two smaller lakes, Lake Sidihoni and Lake Aek Natonang. Across the lake to the east from the island lies Uluan Peninsula.
The largest natural island on an island is Glover Island.
Glover Island is a lake island in the interior of the Island of Newfoundland in the province of Newfoundland and Labrador, Canada. It is the 18th largest lake island in the world by area. The island is located in Grand Lake,a natural lake whose waters were raised for the Deer Lake Power Development.
The largest island in a lake in an island in a lake is Treasure Island (Ontario).
Treasure Island, also known as Mindemoya is a large island in Lake Mindemoya, on Manitoulin Island. As Manitoulin's largest island, it is said to be the world's largest island in a lake in an island in a lake. The island has no permanent residents, but there are some cottages.
The largest island in a lake in an island in a lake in an island is Nameless island in Nunavut.
Victoria Island (or Kitlineq) is an island in the Canadian Arctic Archipelago and straddles the boundary between Nunavut and the Northwest Territories of Canada. It is the eighth largest island in the world, and is Canada's second largest island. It is nearly double the size of Newfoundland and is slightly larger than the island of Great Britain. It contains the world's largest island within an island within an island. The western third of the island belongs to the Inuvik Region in the Northwest Territories; the remainder is part of Nunavut's Kitikmeot Region.
The most populous island is Java.
Java is an island of Indonesia. With a population of 135 million (excluding the 3.6 million on the island of Madura which is administered as part of the provinces of Java), Java is the world's most populous island, and one of the most densely populated places in the world. Java is home to 60 percent of the Indonesian population. The Indonesian capital city, Jakarta, is located on western Java. Formed mostly as the result of volcanic eruptions, Java is the 13th largest island in the world and the fifth largest island in Indonesia.
The island shared by the largest number of countries is Borneo, shared by three countries.
Borneo (or Kalimantan) is the third-largest island in the world and the largest island of Asia. At the geographic centre of Maritime Southeast Asia, in relation to major Indonesian islands, it is located north of Java, west of Sulawesi, and east of Sumatra.
The island is divided among three countries: Brunei and Malaysia on the north, and Indonesia to the south. Approximately 73% of the island is Indonesian territory. The sovereign state of Brunei, located on the north coast, comprises about 1% of Borneo's land area.
The information on this page was taken from Wikipedia and re-written lightly.