White boat crossing majestic antique Luis I Bridge in Porto, Portugal, day

white boat crossing majestic antique porto portugal day luis i bridge rabelo boat mosteiro da serra do pilar cais da ribeira vila nova de gaia douro river seagulls flying landmark european serra do pilar ponte de dom luis dom luis bridge structure architecture europe tourism river water travel bridge urban panorama douro hill medieval old sky portuguese red historical panoramic city landscape evening knoll location sunset site monastery arch