Here's a map I created for a fighting pit, bar & lodging. There is a lower level split into four areas: units for monsters that come up through the grate in the arena, cells for criminals who are slated to fight as well as posh lodging. The fourth area in the lower level is for dining for the "captain" to entertain guests before they watch the fights from his "box."
The ground level has an entrance, bar, and lodging for fighters (along the left). The whole place has a "ship" theme as it is owned by a previous first mate. Feel free to redesign it as you need for your campaign, of course.