Built in 1936 as the Hall of Horticulture for Texas Centennial Exposition in Fair Park - Dallas, the 7.5-acre campus included the first public conservatory in the Southwestern United States. Chartered in 1941 as a 501(c)(3) private, non-profit, Texas Discovery Gardens is the second oldest botanical institution in Texas, and the first in Dallas to offer botanical education programs for children. Since 1995, in conjunction with the State Fair of Texas, Texas Discovery Gardens has hosted an annual live butterfly immersion exhibit.