La Portada

La Portada stands about 400 metres off the coast north of Antofagasta, an arch some 43 metres high cut through a stack whose base is old volcanic andesite and whose upper part is marine sedimentary rock full of fossil shells - the sea floor of a few million years ago, lifted and then carved. It was declared a natural monument in 1990. The stack is being undercut and will eventually fall, which is why the beach beneath was closed to the public after rockfall assessments; visits are from the clifftop terrace above, which has a visitor centre and restaurants. Marine birds and sea lions use the base.

What you actually see

• A 43 metre sea arch - volcanic base, marine sediment above.
• Fossil shells in the upper rock - an old sea floor, lifted.
• A monument since 1990 - protected as a natural landmark.
• Viewed from the clifftop - the beach below is closed for rockfall.

When to go

Year round; the coast here is dry and mild all year. Two hours.

Honest expectations

The beach below the arch has been closed on safety grounds and going down is not permitted. The viewpoint is a terrace with facilities rather than a wild coast. Sea fog can hide the arch in the mornings.

Nearby

Antofagasta is south along route 1; the Atacama coast runs north.