city walls tower in rhens, rhein with a big beach in a hot summer

landmark tower bridge monument tourism river tree reflection waterway mountain vehicle memorial spire water reservoir skyscraper building sea rhens small town mittelrheintal south koblenz medieval roots visible famous königsstuhl view rhine wide parts middle valley used meet holt negotiation local rulers area one king elected 14th century hold kamp-bornhofen city walls rhein big beach hot summer