Building and the Joslyn Castle. There are also three properties designated as National Historic Landmarks. Locally designated landmarks, including residential, commercial, religious, educational, agricultural and socially significant locations across the city, honor Omaha's cultural legacy and important history. The City of Omaha Landmarks Heritage Preservation Commission is the government body that works with the mayor of Omaha and the Omaha City Council to protect historic places. Important history organizations in the community include the Douglas County Historical Society. Sports Sports have been important in Omaha for more than a century, and the city plays host to three minor-league professional sports teams. Omaha has hosted the annual June NCAA College World Series men's baseball tournament since 1950. It has been played at the downtown Charles Schwab Field since 2011. The Omaha Sports Commission is a quasi-governmental nonprofit organization that coordinates much of the professional and amateur athletic activity in the city, including the 2008, 2012 and 2016 US Olympic Swimming Team Trials and the building of a new stadium in North Downtown. The University of Nebraska and the Commission co-hosted the 2008 National Collegiate Athletic Association (NCAA) Division One Women's Volleyball Championship in December of that year. The 2016 Big 10 Baseball Championship was also played at the College World Series Stadium. Another quasi-governmental board, the Metropolitan Entertainment and Convention Authority (MECA), was created by city voters in 2000, and is responsible for maintaining the CHI Health Center Omaha (formerly CenturyLink Center Omaha). The Omaha Storm Chasers play at Werner Park. They won seven championships (in 1969, 1970, 1978, 1990, 2011, 2013, and 2014). Omaha is also home to the Omaha Diamond Spirit, a collegiate summer baseball team that plays in the MINK league. The Creighton University Bluejays compete in a number of NCAA Division I sports as members of the Big East Conference. The Bluejays play baseball at Charles Schwab Field, soccer at Morrison Stadium, and basketball at the 18,000 seat CHI Health Center Omaha. The Jays annually rank in the top 15 in attendance each year, averaging more than 16,000 people per game. The Omaha Mavericks, representing the University of Nebraska Omaha (UNO), also play basketball, baseball and soccer in NCAA Division I as members of The Summit League. The UNO men's ice hockey team plays in the National Collegiate Hockey Conference. Ice hockey is a popular spectator sport in Omaha. The Omaha Lancers, a United States Hockey League