Remagen (including the remains of the famous WW2 “Bridge at Remagen”) and Königswinter.  Rising above the riverside town of Königswinter is the rocky outcrop known as the Drachenfels "Dragon's Cliff" topped by its imposing ruined castle.  Drachenfelsbahn, Germany's oldest cog railway connects Königswinter with the summit of Drachenfels.  Opened in 1883, the railway leads from the bottom of the valley up steep inclines.  A height difference of 722 feet (220m) is covered in one mile (1.6km) of track.