It's an end of an era for an alumni group at the Sioux City’s old Central High School. The Castle on the Hill Association must leave the building they called home for years. Frank Conkey is a volunteer with the organization. “We have been here for 15 years and really took care of our spaces. I’m sure it won’t be the same.” The alumni association sold the former school to the developer from Woodbine, Iowa for $1 in exchange for a 15-year lease that ran out at the end of the year. A representative