Monumento Natural da Pedreira do Avelino

Monumento Natural da Pedreira do Avelino is a dinosaur track site in the municipality of Sesimbra, near the village of Zambujal on Portugal's Setúbal Peninsula. On the face of a former quarry, rock still holds the footprints of animals that walked here around 155 million years ago, in the Late Jurassic.

What can you see here?

The rock preserves tracks of long-necked, long-tailed, four-legged plant-eating dinosaurs, known as sauropods. Researchers describe them across at least four stratigraphic levels. One of those levels shows 108 footprints forming at least five separate trackways. Individual prints line up into sequences that reveal which way the animals were heading and how they placed their steps.

The same quarry has also yielded pterosaur tracks. A 2010 scientific paper by Octávio Mateus and Jesper Milàn reports them from the Kimmeridgian and counts them among the first such finds in the Upper Jurassic of Portugal. The paper also mentions crocodile tracks. Trace fossils of this kind had not previously been known in the country.

How did the site become protected?

The site was found in the late 1980s. In 1997 it received the status of Natural Monument (Monumento Natural). Three dinosaur track sites in Sesimbra municipality are protected this way. The other two are Pedra da Mua and Lagosteiros, both at Cabo Espichel.

Can you visit?

Yes. According to the municipal tourism information, the site is open every day, free of charge and without a guide. There is a viewing platform from which to look at the prints, plus information panels explaining what the tracks are and how they formed. The coordinates are 38.454142 N, 9.123209 W.

Frequently asked questions

Is there an entrance fee? No. Visiting is free and needs no booking or guide.

Which animals left the tracks? Mainly sauropods, large four-legged plant-eating dinosaurs with long necks and tails. Pterosaur and crocodile tracks have also been described in the quarry.

How old are the tracks? About 155 million years. The prints date from the Late Jurassic.

How many footprints are visible? One rock level carries 108 prints forming at least five trackways. In total, tracks occur on at least four levels.

Where can I see similar sites nearby? In Sesimbra municipality, add Pedra da Mua and Lagosteiros at Cabo Espichel to your route; they have the same protected status.

Who is it for?

The site suits families with children, geology and palaeontology fans, and anyone exploring the Sesimbra area who wants to combine beaches and the old town with a short visit to deep prehistory. A visit usually takes little time, so it pairs well with a trip to Cabo Espichel. Bring sturdy shoes, since the former quarry ground is uneven, and a hat, because shade near the platform is scarce.