WorldMark Seaside is located in Seaside, Oregon, WorldMark Seaside is the perfect Oregon Coast retreat. Many accommodations include fully equipped kitchens, color televisions, DVD players, fireplaces, and more. Relax by the heated outdoor pool or stroll along the beach. Seaside is one of the oldest resort towns in Oregon, and is known for the Promenade that stretches one-and-a-half miles long.