Many fjords punctuate Iceland's 4,970-km-long (3,088-mi) coastline, which is also where most settlements are situated. The island's interior, the Highlands of Iceland, is a cold and uninhabitable combination of sand, mountains, and lava fields. The major towns are the capital city of Reykjavík, along with its outlying towns of Kópavogur, Hafnarfjörður, and Garðabær, nearby Reykjanesbær where the international airport is located, and the town of Akureyri in northern Iceland. The island of Grímsey on the Arctic Circle contains the northernmost habitation of Iceland, whereas Kolbeinsey contains the northernmost point of Iceland. Iceland has three national parks: Vatnajökull National Park, Snæfellsjökull National Park, and Þingvellir National Park. The country is considered a "strong performer" in environmental protection, having been ranked 13th in Yale University's Environmental Performance Index of 2012.