Access coming from:

- Alcanena (± 30 km) - N361, N362. Passing Feteira and Mosteiros take direction Fonte Longa / Portela da Teira by 12 de Janeiro street and Principal street. In Fonte Longa follow to Associação street. This one will have another road on the left, there turn right. Continue on this road passing the cross with Casal do Conde street, until you find on the right an old quarry. The columnar jointing is on the right.

- Rio Maior (± 10 km) – take Principal street direction Portela da Teira / Alcobertas. In Portela da Teira follow to Pena da Leixe street. At the cross with Potes Mouros street, take right (not by Potes Mouros street). Follow that road until you find on the right a tight on the right. The quarry and the columnar jointing are on the right.

GPS: 39.404484, -8.913014

The basaltic outcrop of the volcanic chimney of Portela da Teira is perhaps the most representative and spectacular example in Portugal mainland in terms of columnar or prismatic disjunction. These forms result from the retraction of basalt during the cooling and solidification of lava, forming prisms of hexagonal shape perpendicular to the cooling surface.

The nearby basalt exploitation is making this place an extremely vulnerable geossite.

Basalt - dark colored extrusive igneous rock composed chiefly of calcium plagioclase and pyroxene.

Columnar jointing - magmatic rocks in the form of columns due to the appearance of perpendicular cracks resulting from lava cooling.

Joint – a surface of fracture in a rock, without displacement parallel to the fracture.