Santa Maria geology: the fossil quarry, the red clay barreiros and which geosites to see

Santa Maria has 15 sites on the Azores Geopark list, more than you will see on a short stay. Most visitors have a day, or a morning and an afternoon, for the rocks. This guide sorts the geosites by what they show and how easy they are to reach, so you can pick three or four that fit.

Santa Maria is the oldest island in the Azores, with formations dated to about 8 million years. The younger islands show you fresh volcanic landscape. Here the volcano sank below the sea and later rose back out of it, so lava and seabed sit on top of each other in the cliffs. You can see marine fossils in layers that are now high above the water, lava that erupted under the sea, and old basalt weathered into red clay.

The Azores Geopark, a UNESCO Global Geopark, has 121 geosites across the nine islands. Its Santa Maria list runs from SMA 1, the Barreiro da Faneca, to SMA 15, Praia Formosa and Prainha.

The Casa dos Fósseis is part of the Dalberto Pombo Environmental Interpretation Centre at Rua Teófilo Braga 10-14 in Vila do Porto. Dalberto Pombo was a local naturalist, and the centre holds his collections. The fossil section has a 3D film on how the island formed and a game where you play at being a palaeontologist. Go there first: the quarry and the cliffs make more sense once you know what the layers are.

Opening hours and admission were not published on the pages we could reach in September 2026. Phone the centre on +351 296 206 798 before you plan around it.

This old quarry face is the island's best-known geosite and a classified natural monument. It shows a complete underwater sequence. At the bottom are marine sediments packed with fossils. On top of them sit hyaloclastite, which is glassy rubble made when lava meets seawater, and pillow lavas, the rounded blobs lava forms when it erupts underwater. The whole sequence is about 5 million years old.

A wooden footbridge crosses the clifftop fields to the site. The quarry is on the south coast west of Praia Formosa, and the PR05SMA coastal trail passes it.

The fossils are protected, so photograph them and leave them in the rock.

A short way along the same coast, the Figueiral cliff shows lava flows, ash layers, dykes and fossil-bearing sediment. At about 100 m above the sea is one of the largest sedimentary outcrops on the island, also around 5 million years old.

The cliff was also mined. The Gruta do Figueiral is an old gallery where limestone was cut for lime and clay for roof tiles, and an old lime kiln stands nearby. At the western end of the geosite is a sea cave, the Furna Velha or Furna das Pombas, which is 337 m long and up to 14.5 m high. It was cut by the sea, and nothing on the geopark page suggests a way into it on foot.

The simplest way to see Pedreira do Campo and Figueiral together is the PR05SMA trail. It runs 8 km along the south coast from near the 17th-century São Brás fort in Vila do Porto to Praia Formosa, takes about three hours and is graded medium. It is linear, so arrange a taxi or a lift back.

One stretch of the coast is exposed. The official register warns of vertigo there and has fixed a steel cable to hold on to, and it signs an inland alternative for stormy weather. The trail ends at Praia Formosa, the beach with pale limestone sand found nowhere else in the Azores. Our guide to Santa Maria's walks covers the other routes.

Santa Maria's red "desert" areas are called barreiros, and there are two of them on the geopark list.

The Barreiro da Malbusca is on the south coast. It is a bare, strongly red clay slope formed from a lava flow that weathered away under a thin layer of volcanic ash. Look at the ground: the small, black, smooth pebbles scattered on it are manganese nodules from an old beach that now sits about 130 m above the sea. Near the top of the cliff you can see the original lava flow with its column-shaped jointing, and rain has cut small gullies into the clay.

The Barreiro da Faneca, on the north coast, is the bigger and better-known one, a protected landscape since 2008 covering 8.35 km². The red clay comes from basalt that weathered in a hot, humid climate several million years ago. The PR01SMA Costa Norte trail crosses it.

• Poço da Pedreira is an abandoned quarry in old, heavily weathered volcanic cinder. The cinder has stuck together and turned red, which is why the quarry walls stand so steep and why the cone is called Pico Vermelho, "red peak". The PRC03SMA loop from Santa Bárbara passes it.
• Ribeira do Maloás is a waterfall of 15 to 20 m about 220 m up the stream from its mouth. The lava it falls over cooled into vertical columns, some almost 1 m across, and the tops are cut flat like the Giant's Causeway in Ireland. You reach it on foot and it is easy walking, but there is no car park at the site. There is no fee and no timetable.

The island's south-east point is a high, steep sea cliff that shows most of the island's history in one section: marine sediments with fossils, lava that erupted underwater and on land, and dykes cutting through all of it. Its fossil sandstone has been protected by regional law since 2018. Of all the sites here, it is the one where a visit to the House of Fossils beforehand helps most.

• Morning: the House of Fossils in Vila do Porto, then walk PR05SMA past Figueiral and Pedreira do Campo to Praia Formosa and swim.
• Afternoon: taxi or drive to Ribeira do Maloás and the Barreiro da Malbusca, and finish at Poço da Pedreira.
• A second day, if you have one: PR01SMA across the Barreiro da Faneca on the north coast.

The Associação de Taxistas de Santa Maria answers on +351 296 882 199.

What is the best geosite on Santa Maria? Pedreira do Campo. It shows fossil-rich seabed under lava that erupted underwater, about 5 million years old, and a wooden footbridge leads to it.

Where can I see fossils on Santa Maria? In the field at Pedreira do Campo, Figueiral and Ponta do Castelo, and indoors at the Casa dos Fósseis in Vila do Porto. The sites are protected, so do not collect.

Is the Barreiro da Faneca the only red desert? No. The Barreiro da Malbusca on the south coast is a second red clay area on the geopark list, with manganese nodules from an old beach now 130 m above the sea.

How long do I need? One full day covers the House of Fossils, the south coast trail and two or three stops by car. Add a day for the north coast and the Barreiro da Faneca.