Like the other azorean islands, Terceira island is of volcanic origin, with a variety of forms, rocks and unique structures.
To the east, there is an extensive plateau, and the small hills of Serra do Cume, where you can enjoy excellent panoramic views of the island..
At its centre, there is the Guilherme Moniz Caldera, a small crater albeit with a perimeter of 15 km (the biggest of the archipelago). Here you can find the vestiges of the volcanic activities on the island, which are spectacular and can be easily visited. Algar do Carvão is a volcanic chimney and is overwhelming for its immense space. From its arched roof hang strange and remarkable silica stalactites. The Gruta do Natal, a cave consisting of a lava tube, is a wonder for its extensive, straight, long passages. The walls, ground and ceiling have different colours and shapes, transforming the cave into a mystic place. Outside, there are the Furnas do Enxofre, caves which are today’s witnesses of the formation of the Archipelago. The landscape is filled with fumaroles, surrounded by a red soil contrasting with the green of the moss. The whole atmosphere is warm, with a characteristic smell.
To the west, there is the outline of the hills of Serra de Santa Bárbara that is 1023 metres high and includes lakes, caves and some hidden Mistérios Negros (Black Mysteries), amongst dense flora waiting to be discovered. From Serra de Santa Bárbara you can enjoy the magnificent scenery of Terceira Island and surrounding islands.
For visitors in general, the island offers the tranquility of their various shades of green scattered through fields and pastures, broken by an almost geometric modulation stone walls and hedges of hydrangea.