There are many things to love about New York’s venerable subway system, but eye-popping design ain’t one of ’em.

Unless you know how to find the secret City Hall 6-train station, that is. Betcha’ didn’t know this underground cathedral was hidden under your feet this whole time (we sure didn’t):

Originally designed in 1904 as a showpiece for the Interborough Rapid Transit Company’s “Manhattan Main Line,” the station was boarded up in 1945. The city started restoring the City Hall station as a transit museum prior to 9/11, but security concerns killed the plan. The station is still closed to the public. Here’s an old diagram showing its location in relation to the Brooklyn Bridge station. The City Hall station is in the big loop on the left.