Underneath Paseo de Peralta, near the heart of downtown Santa Fe, are two half-mile concrete tunnels that comprise the city's Arroyo Mascaras system. For decades they've served as a refuge for artists, drifters, high school partiers and anybody else who, for whatever reason, needs to dip underground for a bit.

The passageway is completely dark, and the ground is beach-sandy. We went down with an iPhone flashlight and the flash of a camera, following the path to an open gully that runs alongside Paseo de Peralta and crosses St. Francis Drive. The arroyo system then passes by Gonzales Community School before emptying out into the Santa Fe River.

Known as "Heaven and Hell," the tunnel to the left is Heaven and the one to the right is Hell. Naturally, we chose the latter. The Santa Fe County Assessor's office doesn't even list an owner for the land constituting the arroyo. Its history is more local legend than city document.

One painter who arrived to Santa Fe in the mid-1990's says older and younger artists waged a years-long turf war over canvas space in the tunnels. In the early days, he says, he mostly partied in the mouths of the tunnels, and only painted on its concrete edges to preserve the work of older artists.

"The deeper you went [into the tunnel], some of the younger locals started to find it and painting the uncharted parts, and there were quarrels between younger and older guys," the artist, who wishes to remain anonymous, tells SFR. "But for a while it was just all respect and they all kind of shared it, but as generations go on, it gets watered down, and now it's kind of like [a] free-for-all."

Besides some liquor bottles and empty chip bags half-buried in the sand, there weren't obvious signs of life when we ventured down there—no skunks, spiders or snakes. The sound and sight of our quick approach may have scattered any people or critters before we had a chance to meet. Our inclination was to keep moving.

The scrawling on the walls became more chaotic the deeper we moved into the tunnel. The unspoken rules that once governed canvas boundaries no longer apply; borders have collapsed, and pieces are free to exist in any patch of grey concrete their creators can find, or even on top of another artist's work. It raises several questions: How can spatial freedom co-exist with respect for another person's space? Is seniority alone a worthy basis for earning somebody's respect?

Check out our photos and Go-Pro footage below. It would be stupid to venture inside while it was raining or otherwise wet, so please, don't do that.

The entrance to Hell.
The entrance to Hell.
The beginning.
The beginning.