São Miguel Island, also known as the "Green Island," is the largest (759 km2; 293 sq mi) and most populous of the Azores Islands. The island has around 140,000 inhabitants, most of whom live in the municipality of Ponta Delgada, the most populous place in the islands.

The Sete Cidades twin lakes are lakes formed in a crater that has a perimeter of 12 km (7.5 mi).