Federal Hill seems to be one of those places where the more things change, the more they stay the same. So it is with the tunnels in the hill, which pop into public notice every few decades. The contractor shoring up the unstable north face of Federal Hill Park unearthed a large cavern 20 or 30 feet below the surface. Meticulously carved and arched, it runs some 200 feet, with a large chamber. An archaeologist got a quick look, and the entrance was quickly sealed before the curious could get in.
Existence of tunnels under the park and, indeed, under a considerable area of the surrounding neighborhood, has long been documented. The surprise was that this tunnel, so close to the north face, still exists. The slope has been altered or shored up repeatedly because its clay and sand are unstable, slipping down into what is now Key Highway periodically for well over a century. In fact, the city took it over as a park in the 1870s largely to prevent further damage.
Other tunnels have made themselves known over the years by caving in -- sometimes inconveniently under someone's home. Records are spotty, so the purpose, extent and location of the tunnels have long been a neighborhood guessing game and a topic for more serious study by local historians. The best guess ++ about the latest find is that it was excavated by a glass manufacturer at the foot of the hill for its fine sand.