Located 55km southeast of San Pedro, the Atacama Large Millimeter/submillimeter Array (ALMA) consists of 66 antennae, most with a diameter of around 12m. This field of interstellar ‘ears’ simulates a telescope an astonishing 16km in diameter, making it possible to pick up objects in space up to 100 times fainter than those previously detected.
Contact the ALMA Visitor Center to visit. It's free but guest numbers are limited; register online. A free shuttle from Tumisa near Ave Pedro de Valdivia provides transportation to the facility, leaving at 9am and returning at 1pm Saturday and Sunday.