sentences:  They founded Camp Alvernia in Centerport, New York, in 1888, which remains the oldest Catholic summer camp in continuous operation in the country.They now also operate several facilities for spiritual retreats on the grounds, including Mount Alvernia Retreat Center.In the early 1920s, the camp was the site of an anti-Catholic demonstration by the Ku Klux Klan, which conducted a cross burning on its grounds.