The exceptionally well-preserved picturesque work of Jan Joost van Cossiau, which has remained in the possession of Count von Schönborn to this day, offers an unusually good opportunity to illustrate the essence of late Baroque landscape painting and its adherence to models, up to the direct adoption of foreign inventions. Additionally, a vivid picture emerges of the collecting passion and patronage of the Mainz Elector Lothar Franz von Schönborn.