mariental castle or fortress bip “great toy of paul” on shore of slavyanka river in marientalsky park at bright sunny autumn

architect architecture autumn bastion bip brenna building castle coast colourful colours day duck emperor exterior fall fiery flag foliage fort fortress gate great historical landscape leningrad lock marientahl mariental marientalsky mary nature park paul pavlovsk petersburg picturesque pond reflection region river roof russia russian saint shore sky slavyanka spire suburb tower toy valley vincets water window