One of the main attractions in Delta is the Old Stone Mill National Historic Site. Built in 1810, the old mill has been restored to its former glory by the Delta Mill Society, a non-profit volunteer group. The mill is open to the public from the Victoria Day long weekend in May to Labour Day in September and during special Delta events (Maple Syrup Festival, Delta Harvest Festival and Celebrating the Season). In addition to its impressive architecture, it features an operating water wheel and mill stones. Heritage grain is ground into flour using the old mill stones several times during the season.