General Knowledge
Island or Mainland Quiz
Surrounded by water or connected by land — can you tell the difference?
Surrounded by water or connected by land — can you tell the difference?
Indonesia is the world's largest archipelago with over 17,508 islands — but only about 6,000 are inhabited. The distinction between island and mainland isn't always as obvious as you'd think. Is Manhattan an island? Is Istanbul? What about Singapore, which is connected to Malaysia by a causeway?
This quiz explores the fascinating geography of landmasses, from the technical definition that makes Australia a continent rather than an island, to places like Mumbai that were originally islands before land reclamation connected them to the mainland. You'll discover that Borneo is shared by three countries, that Madagascar separated from Africa 88 million years ago, and that the world's longest tunnel connects two Japanese islands.
From Greenland (the world's largest island at 2.16 million sq km) to tiny coral atolls, these 50 questions cover island geography, peninsulas, archipelagos, and the sometimes surprising classification of famous places. Whether a location is truly an island or connected to the mainland is more nuanced than you might expect.
Australia is classified as a continent, not an island. At 7.7 million square kilometers, it sits on its own continental plate and is roughly 3.5 times larger than Greenland, the world's largest island. The conventional cutoff between 'island' and 'continent' places Australia firmly in the continent category, though the distinction is ultimately a matter of geological convention.
Greenland is the world's largest island at approximately 2.16 million square kilometers. Despite its enormous size — larger than many countries — it remains an island because it sits on the North American tectonic plate rather than its own continental plate. About 80% of Greenland is covered by an ice sheet up to 3 km thick.
An island is a body of land completely surrounded by water that is smaller than a continent. Mainland refers to the principal landmass of a country or continent, as opposed to its islands. The distinction gets complicated with peninsulas (connected by a narrow strip of land), artificial land bridges (causeways), and places that were once islands but were connected through land reclamation.
Last updated: April 2026