The landmark Brooklyn Heights building built in the 1920s and then used by the Jehovah's Witnesses since the '60s is officially up for sale.

The religious group is relocating its headquarters to upstate New York. Officials offered a tour of the iconic building and other properties Wednesday.

"The properties come up once in a generation," says Watchtower spokesman Richard Devine. "There won't be too many opportunities like this in Brooklyn again simply because of their location, their beautiful condition and potential future uses they might have."

The group will begin the transition to its new location in the fall.