The trail to the Shrine of Raban Boya and some other sites of interest is located next to the firehouse, and a twenty minute walk from the Shaqlawa bazaar.
It is a fantastical journey up Safin mountain.
Once you cross through the fortress-style gate, the first sight on the path to the cave is a small chapel surrounded by a graveyard. Going through on a Saturday morning, I found the graveyard was quiet and the chapel was closed and neglected. I thought it was perhaps used just for funeral services.
Directly above the chapel and graveyard is a stone structure over the grave of Shamoun Shaqlawi. No other information was immediately available.
As the asphalt road gives way to a stepped path, and then eventually a dirt trail, the cave itself becomes apparent. Once you finally are the beneath the cave and see the arch above you, all that remains is the last path (with a metal railing) where you'll see greasy drippings of countless votive candles.