Set against the rugged backdrop of El Potrero Chico, “When the Cat's Away, the Rats Will Play” offers an intriguing blend of adventure and solitude for climbers ready to test their wits on a route that demands both patience and persistence. Located in the northern reaches of Mexico’s Nuevo Leon, this sport climb stretches 420 feet over four distinct pitches, each presenting its own character within an isolated pocket of vertical rock.

The climb starts modestly with a 5.9 pitch that threads the left side of a narrow gully, moving upward with a shorter but confident pull. Here, you’ll feel the mountain’s temperament—scattered loose rock reminding you to stay deliberate with each hold. The second pitch ramps up the technicality with a 5.10d face climb adorned with bolts spread along chimneys and corners, requiring careful balance and steady footwork amid less-than-perfect rock quality.

Ascending further, pitch three shifts back into a gully-like channel leading to a dusty ledge. From this resting spot, you negotiate past old rap anchors before embarking on another face climb at 5.10c. The handholds remain sparse but positive enough to keep you moving without hesitation. The final pitch unravels into the most enjoyable section—a 5.10a face peppered with solid, positive holds where the climbing feels more in tune with your rhythm and less about wrestling the rock.

Approaching the summit reveals a short but unprotected scramble that demands caution. Loose stones litter the entire climb, intensifying the need for vigilance, especially on the upper pitches where the terrain grows more unstable. The payoff at the top is a quiet summit, rewarded with wide, unspoiled views that hang over El Potrero Chico’s expansive valley.

From a practical standpoint, this climb favors those comfortable with moderate runouts and a willingness to navigate imperfect conditions. Bolts protect the ascent, but the presence of loose rock compels climbers to maintain controlled movements and safeguard partners with clear communication. The route sits in a semi-remote sector of El Mirador, lifting energetic spirits with its blend of exposure and a chance to escape busier climbs nearby.

Timing your ascent in the cooler morning hours eases the intensity of the sun-facing wall, as shade is minimal throughout the day. Prepare with sturdy approach shoes for the talus-filled trail and pack enough water to stay hydrated under the dry northern Mexico heat. Though the rock quality varies, the experience of climbing a quieter, less trafficked route in one of North America’s classic limestone areas gives ample reason to brave this playful but gritty challenge.

Whether you’re honing your technical face climbing or seeking a scenic summit far from the crowds, this route offers a layered adventure. It may not provide polished perfection, but it promises the rewarding feeling of testing yourself against raw, honest terrain where nature still calls the shots.