In a park on the outskirts of Colombia's capital, Santiago Abril set up a mat made with interlocking rubber panels and assembled an octagonal structure resembling a mixed martial arts cage.

The portable ring, made of rubber and plastic, serves as the stage for the improvised boxing matches that Abril has organized for months at parks in Bogota, mostly without official permits.

Dozens of young men and women gather on weekends for Abril's pop-up fights, where strangers face off without the lengthy preparations required for regular boxing matches.