Terceira Island

Terceira is the third-largest island in the Azores and home to Angra do Heroísmo, the only urban settlement in the archipelago with UNESCO World Heritage status for its colonial-era streets and fortifications. Beyond the historic capital, the island's interior contains the Algar do Carvão, a lava tube and magma chamber open to visitors, and the Serra de Santa Bárbara caldera rising to 1,021 metres. Terceira's central position in the archipelago made it historically significant as a waypoint for transatlantic navigation.