3er arco (3rd arch) is the third album by Argentine rock band Los Piojos.

It was officially presented at the Arpegios Theatre.

It is included in "The 100 best argentine rock albums" as listed on the Rolling Stone magazine.

The Allmusic review by Stephen Thomas Erlewine awarded the album 4 stars stating "3er Arco finds the Argentinean band Los Piojos -- composed of Daniel "Piti" Fernandez, Daniel Buira, Miguel Angel "Micky" Rodriguez, Gustavo Kupinski and Andres Ciro Martinez—at the peak of their form, turning out an imaginative fusion of Latin rhythms and hard rock.

It's their finest moment to date and the best way to become acquainted with the band.