Are you longing for an outdoor adventure that takes you off the beaten track? Our state is known for some incredible cave systems, but the most unique cave in Washington sits along State Route 821, a scenic byway in the Yakima River Canyon. It may not be the most famous, but Yakima's Graffiti Cave is well worth a visit, especially if you've got a soft spot for offbeat roadside attractions.

Though it's just an hour long, Route 821 treats drivers to incredible views of the shrub-steppe environment. Graffiti Cave is just north of Yakima, sandwiched between some of the region's best hikes. If you're already planning a day in the area, it makes an excellent amuse-bouche.

You'll pull off the highway and head up the hill via an abandoned road. This path deposits you at the mouth of a derelict tunnel.

All along the way, graffitied rocks speckle the path. Despite my attempts to learn more, finding reliable sources on Graffiti Cave is challenging. Who was first to visit and tag the tunnel isn't known, but clearly the practice developed over time, becoming a local tradition.

In the cave, the walls are covered with years worth of artwork. There's no telling what you might see or if you'll see it next time you come. It's worth noting that visitors are prohibited from entering the tunnel. Still, some folks do so routinely.

Though it seems local officials go soft on artists tagging Graffiti Cave, graffiti has become a pervasive issue at our state's other caves. In the Mount St. Helens National Volcanic Monument, Ape Cave has been repeatedly vandalized, threatening the fragile cave ecosystem and forcing park closures.

Luckily, Graffiti Cave is not an essential habitat for local species, so the artwork here has had far less impact. Regardless, it's best practice to experience the cave as a visitor, not as a contributor.

When I visited, I found Graffiti Cave unexpectedly moving. There's something innately human in the drive to leave our mark. So long as that desire doesn't affect local wildlife, it's relatively harmless. Looking at all the pictures and messages left by people passing through, it's impossible not to feel that they're speaking to the future. Graffiti is ephemeral— the art is guaranteed to get covered up— but it's still an added chapter to the cave's ongoing story.

If you're in the area, pack your gear and walk up to this unique cave in Washington! Though I don't recommend contributing, people have tagged Yakima's Graffiti Cave for years, transforming it into an utterly unique roadside attraction.