As the group or just Lucca arrives at the address, it's actually pretty hard to miss the building Samahs was referring to--it's a cathedral. Small, but a cathedral nonetheless. There's a large holy symbol beautifully shaped out of stained glass atop the wide set of double doors leading into the building colored almost to resemble the sun on a bright day.
As you enter, the inside is immediately very spacious, even more than you would have expected from seeing it on the outside. The walls are covered in paintings primarily of landscapes and the holy symbol of the dawnflower. There is a podium and a stage at the front of the room and a second story balcony stretching around the top of the room. There are several doors the lead into rooms outside of this central one.
There are a small number of priests and monks, perhaps 5 or 6, that are sitting and reading or walking around the center room at a brisk pace. All of them seem to be unaware that you've entered their church.