University of Dayton Arena (commonly known as UD Arena) is a 13,435-seat multi-purpose arena located in Dayton, Ohio. The arena opened in 1969. It is home to the University of Dayton Flyers basketball teams. From 2001 to 2010, the facility hosted the annual "play-in" game in the NCAA men's basketball tournament (officially the "opening round" game) which featured the teams rated 64th and 65th in the tournament field. Beginning in 2011, when the tournament expanded to four opening-round games, the arena continued to host all "first four" games. Overall, the arena has hosted more men's NCAA Division I basketball tournament games than any other venue.