ANKARA/ISTANBUL As the massive works of Peter Paul Rubens and Rembrandt are restored before the eyes of visitors, the experts involved describe the unique experience as both "inspiring and stressful." Rembrandt's The Night Watch and Peter Paul Rubens' Enthroned Madonna Adored by Saints stand out as two monumental works in art history. Rubens' painting, displayed at the Royal Museum of Fine Arts Antwerp in Belgium, measures 6 by 4 meters (20 ft x 13 ft), while Rembrandt's masterpiece, located in