On top, you're looking east from the roof of the Hotel Nassau. In the immediate foreground on the left is the The Castle Baths building, (later the Mirimar Apts) just beyond it, with the white columns, is the Castle by the Sea dance hall. The dance hall was built by William Reynolds before his corportation when bankrupt and was originall called "Danse de la Mer" (literally, Dance of the Sea). It had the largest dance floor in the world at the time.  It was renamed by the famous ballroom dancers of the day, the Castle's. It burned to the ground in the 30's. On the bottom is yet another postcard view of the Hotel Nassau, this one a little unusual because it is taken from across Broadway on the street side. The corner of the building on the lower left is most probably the Tower Baths, which burned in the 60's.