Smaller than you would expect for a big city, but a great place for an older toddler and younger kid to get some energy out. Don't plan on spending more than 2 hours. We will return as we often make overnight trips to university circle and need a place to run the kids. On other review sites there are a lot of complaints about it being dirty. These people are insane, it is exactly as clean/dirty as any children's hands-on facility.