While not in Antofagasta proper, but rather 25km north of the city, this enormous offshore arch – the centerpiece of a 31-hectare protected zone – is the most spectacular of the area's sights. Topped by marine sediments and supported by a sturdy volcanic base, the stack has been eroded into a natural arch by the stormy Pacific. It's situated on a short westbound lateral off the highway; there's a restaurant, a small Conaf-managed museum and cliff-top views over surrounding beaches.
Take micro 129 from Antofagasta's Terminal Pesquero to the junction at La Portada, and then catch the connection (these run in the busy summer season only) or walk 3km west.
