Gruta do Caldeirão

Gruta do Caldeirão is a cave in the municipality of Tomar, central Portugal, listed as a cultural heritage monument and counted among the country's key archaeological sites. It sits in a limestone massif a few hundred metres from the Nabão river. For anyone drawn to prehistory, it is a place where stacked layers of sediment record many thousands of years of human presence.

What makes Gruta do Caldeirão special?

The cave preserves deposits about 6 metres thick. The successive levels hold traces of the Mousterian, the Early Upper Palaeolithic, the Solutrean, the Magdalenian and the Neolithic. That gives researchers a rare, direct transition from the late Palaeolithic into the Early Neolithic. The sequence also lets scientists compare human occupation with the climate swings of the last glaciation.

Who excavated it, and what did they conclude?

João Zilhão of the University of Lisbon dug here from 1979 to 1988. In 1992 he published the Early Neolithic results as the monograph "Gruta do Caldeirão: o Neolítico antigo". In 2021 a team reporting in PLoS ONE presented new radiocarbon and luminescence dates and found the stratigraphy to be well preserved. They also noted that Magdalenian-age layers were partly disturbed when people buried their dead in the cave during the Early Neolithic.

What was found inside?

In the Neolithic the cave served as a burial place. Remains of over a dozen individuals come from the later Neolithic phase, accompanied by plain pottery vessels, ornaments and polished axes. Researchers have also traced the flint sources of Solutrean stone tools and studied animal and mollusc remains. Beaver bones appear among the fauna, a sign that the landscape around the cave once looked quite different.

How to plan a visit

Tomar lies roughly 130 km north-east of Lisbon and is easiest to reach by car or train. The cave is a research site rather than a developed tourist attraction, so ask the Tomar municipality about access before you set out. Pair the trip with the town itself, home to the Convent of Christ and the Templar castle.

Why does it matter?

The continuity of its deposits and their good condition make the cave a regular reference in literature on the Palaeolithic and Neolithic of the Iberian Peninsula. If you want to follow how life changed from the last Ice Age to the first farmers, this is one of the region's central sites.

Frequently asked questions

Where is Gruta do Caldeirão? In the municipality of Tomar, in a limestone massif near the Nabão river.

Which periods are represented? From the Mousterian and Early Upper Palaeolithic through the Solutrean and Magdalenian to the Neolithic.

Who excavated it? João Zilhão, from 1979 to 1988; the findings were re-examined in a 2021 publication.

Can tourists enter the cave? It is an archaeological site with no described visitor offer. The Tomar municipality can tell you about access.