people promenade at river rhine with view to historic fortress ehrenbreitstein in koblenz

koblenz ancient architecture building castle city ehrenbreitstein europe famous festung fort fortress french funicular germany hill historic history landmark landscape medieval monument mountain nature old outdoor rhein rhine valley river sky tourism tourist town travel unesco world heritage view wall people promenade september 2023: vacation sea beach coast waterway bay walkway vehicle shore dock water resort marina tree lake boat