Eiro concentrated on the way that his breath caused quiet whistles inside of this hidden hallway as well as the vibrations in the air that he strengthened to be able to figure the shape of this place out. The footsteps and voices from other patrons and the Inn-Workers helped with this even more. It took him around a quarter of an hour to completely understand this building and the mechanisms of the hidden passages, but there was a space that he still didn't quite figure out perfectly.
It seemed to be a fair bit underneath this building and had numerous tunnels spreading out in any direction. Knowing about those might be pretty useful, but Eiro hoped that they would be able to leave before needing to use those.