Decoding the original cast-iron subway entrance that’s been on a Brooklyn corner for 110 years

From afar, the R train subway entrance at the northwest corner 77th Street and Fourth Avenue in Bay Ridge doesn’t warrant a second glance. It looks like any other street-level entryway, with the Helvetica signage, the concrete staircase, and the no-slip step tread at the top of the stairs. But look closer, and some unique details emerge—like the unusually thick cast iron sides of the entrance. On those slightly rusty cast-iron sides, you can see strange design motifs. One appears to be a cross, and under the cross a series of rings. The spikes on the back of the entrance are also curious. Is it part of the design, or a way to keep people from sitting down and lounging around? With all of these odd features, it’s clear the 77th Street entrance belongs in another era. A little backstory from the archives and an early photo of the station offer some clues. The station opened in 1916, part of the BMT Fourth Avenue extension that brought subway service to Brooklyn neighborhoods like Sunset…