The three-story Lindenwold Castle in Ambler, once home to 'Asbestos King' Richard Mattison, is up for auction with a starting bid of $1.5 million. The vacant mansion, modeled after the royal Windsor Castle, is surrounded by upscale residences. It recently underwent utility upgrades and has tentative plans approved fora buyer to renovate the castle into 11 apartments and ground-floor commercial space. The castle is on the National Register of Historic Places.