The old railroad junction town of Slateford, Pennsylvania is, at first glance, the type of place one might pass through on a drive into neighboring New Jersey, or bypass completely on the adjacent interstate—but even then the viaduct looms.

“Welcome to Alice” is roughly scrawled at the base of one of the legs of the now defunct Delaware River Viaduct, lovingly dubbed, “Alice,” or “Wonderland,” by locals who trespass on its grounds. It is hard to ignore the concrete relic standing with its concrete legs in the Delaware River.

Measuring 65 feet tall from the base to the top, this landmark was originally meant to connect the Lackawana Cutoff Line from New Jersey, over the Delaware River and up through Pennsylvania into Scranton. Now, after the rails were finally removed in the late 1980s, the bridge serves as a hidden point of interest for locals who know which rocks to climb, and which hollow concrete pillars are safe enough to venture down into.

After crawling through some brush, up the steep hillside and over the stacked highway medians placed there to block the path of curious travelers, you arrive on the top of the bridge, where the railroad gravel is still set. Up ahead, and interspersed over each pillar are open manholes— some with ladders, others with only a sheer drop into the gloom below, with the graffiti adorning one iron lip, urging visitors to “Let Go.”

The interior of the one of the more popular concrete pillars has been charmingly christened “Hitler’s Closet.” It diverges into two paths with a window ledge leading to an outside arch, some 40 feet up, and an old wooden door leading to the higher viaduct arches that overlook the river. Over the years since its closing, graffiti has overtaken much of the concrete wall space. Lines from the Jabberwock are scrawled in Hitler’s Closet, and select lines from Dante’s Inferno can also be found in bright coral blue on the outside wall, “Abandon all hope, ye who enter here.”

Not far away, another illustration of a Cheshire cat winks at visitors in faded yellow, painted on the cracked vaulted ceiling. The fantasy creature is encircled by a cloud of weed smoke emanating from his spray painted joint. Despite the name, Wonderland this is not.