Closed in 2021, this site — formally known as the Wilkins-Rogers Mills — was the last of many that turned Ellicot City into a milling town during the Industrial Revolution. Today, the building is still accessible from the street. There is a corrugated metal overhang that you can easily crawl under. External fire escapes and broken windows provide access to the full interior, though I haven’t tried entering myself. 

In the 1950s, they were functioning sand filtration silos with underground catacombs with sand banked knee-high at the corners. In 1987, they were long abandoned and sold to the District, where they would sit for thirty-seven years as nothing more than a spot for DMV urbex. In 2024, they were renovated into a public park for families— and not only that, but a sand silo-themed playground.

If urbex is nothing more than a playground for grunge adults, McMillan Reservoir is a rare success story. After over three decades of decay, it would have been a typical urbex storyline for the park to be bulldozed to make space for something new and clean. Instead, the district chose to preserve the silos and catacombs. As quoted in this Washington Post article at the time of the renovation:

It gives the 6.2-acre park somewhat of an otherworldly feel, an unlikely cross between industrial and recreational. From the indoor pool, you can peer through the glass windows into the eerie catacombs, which once held sand for the city’s 20th-century water filtration system. The city leaned into the theme: The playground has a sandpit, a slide that pays homage to the shape of the silos, and a miniature play “regulator house” that mimics the brick control rooms next to the old sand towers.

To visit, you can enter McMillan Sand Filtration Site into your GPS. It's located at the corner of Michigan Avenue and North Capitol Street in Washington, D.C.

Welcome to my favorite adventure site in Chicago, the ancient Damen Silos! Located at 2860 S Ashland Ave on the south branch of the Chicago River, they're relatively easy to get to without being super public. The easiest way to access the Silos is by taking the Orange Line on the CTA 'L' train to Ashland. If you are driving, this website gives detailed instructions for parking at a nearby Target.

From the L stop (or parking lot), walk through the business park until you're halfway down the fence and crawl through the hole directly across from the warehouse. You should see something similar to the images above - that's how you know you're at the right place. Once inside the fence, you can explore the abandoned warehouse and silos without much trouble, as long as you keep inconspicuous.

Offering its own sort of adventurous charm, the warehouse has three crumbling floors of colorful graffiti and artistically-disheveled metal. If you were a fan of Milwaukee Wisconsin's Solvay Coke & Glass factory (rest in peace, my friend), you'll absolutely love this place. The building is almost identical in structure.

Climb in through the hole pictured above (located on the silos' north side) and explore the cavernous tunnels of the silos! The amount of rooms and walkways seems endless, so be careful not to get lost. If you have stronger upper arms than me, you can probably climb to the top on the rope, too. It's located on the building's exterior on the river bank side, accessible and hidden from view.

If this place's risk-of-getting-you-arrested was on a five-star system, it would be a solid two. There's a security guard that patrols the site and does a few rounds at night, but he's fairly easy to avoid. He sits in a car with a flashing green light at the top, but he'll turn off the light if he's trying to sneak up on you. I haven't been caught by him, but some friends who have said he just gave them a stern warning and told them to leave. Doesn't sound too risky to me! Nevertheless, be careful swinging your flashlight or taking pictures with flash if you're visiting at night. The windows in both locations make it easy to give yourself away.

I know WAY TOO MUCH about this wild place. How much, you ask? Click here to read one of the longest essays I've ever written about the history of the Damen Silos. It's entertaining, I promise.