The Danube River meanders from central Europe down through Budapest, finally to end in a Black Sea delta in southeastern Romania. The photo below shows the Danube at blue-hour-into-night looking towards the Chain Bridge and Hungarian Houses of Parliament as the river curves through central Budapest, Hungary.
The next photo shows the Elizabeth Bridge, also across the Danube in central Budapest, as dusk has deepened. The solid lines are boats on the Danube. I was helped to find locations by ace night photographer and guide to Budapest Miklos Mayer, who also helped me get into location on the following evening for the fireworks display for Hungarian National Day. If you visit Budapest with your camera, and want to make some special images, Miklos is highly recommended.
Finally, the photo below is a three-exposure monochromatic HDR blend of the central part of the parliament building from right across the Danube River.