The Mezzanine Of Pointlessness

Half of the floor of the Bathroom of Weirdness was raised about three inches.  We always assumed that this was to enable a decent drainage fall from the shower, or the sink, or something.

I've now removed most of it, gingerly*, expecting pipes at any moment, and there's nothing under it other than the 'ordinary' floor.

*well, as gingerly as you can be with a crowbar.