Breiðamerkursandur is a glacial outwash plain in southeast Iceland, known for its sandy terrain and emerging vegetation. Formed by glaciers like Breiðamerkurjökull and Fjallsjökull, this area was shaped during the little ice age as the glaciers advanced down to the lowlands, leaving behind gravel deposits. The famous Jökulsárlón lake, a popular tourist spot, sits on this plain. Breiðamerkursandur is now part of Vatnajökull National Park, offering a breeding ground for birds like Arctic terns and great skuas.