The 78-year-old William Penn Annex Post Office at Ninth and Market Streets in Philadelphia — known for its stunning Art Deco interior — shut down permanently at noon Saturday and will move all postal services to the Cast Iron Building at 718 Arch St. as part of a cost-saving program. There will be no change to post office box numbers or zip codes.

"It's a huge building, and we're not fully utilizing all the space that we're renting," said Postal Service spokesman Ray Daiutolo. The Postal Service had been leasing the space in the six-story Robert Nix Federal Building — what had been the city's last remaining publicly accessible grand postal hall — from the U.S. General Services Administration.

Nick Hayman, who recently moved to Philadelphia from New York City with his partner, Jenny Robbins, said he learned of the move Saturday morning.

"It's grandiose, and the echoes inside, it just sounds like it's from back in the day," Hayman said while taking photos of the building. "I hope they don't destroy everything inside."

The GSA had been focusing on federal agencies as possible replacement tenants, a spokeswoman told the Inquirer and Daily News last August. An update from agency was not immediately available Saturday.