# Seaside Citadel Seaside Citadel is a dual land that produces white, blue, or black mana, making it a utility piece for three-color decks across multiple formats. Collectors view it as a functional reprint of Arcane Sanctum with identical mana-fixing capabilities, so the appeal lies mainly in set completion rather than uniqueness. The Modern Masters 2017 printing is relatively accessible since it was printed at uncommon, keeping both nonfoil and foil copies affordable. Foil versions hold modest premiums over nonfoil due to limited demand. This card matters primarily to players building budget three-color decks who need reliable mana bases, rather than to collectors seeking rare or historically significant pieces.