We've been learning about a lot of rivers throughout Europe, and we know how important they are to how a city develops over time.
Have a look at some of these paintings of the Thames over many years in history, perhaps compare it to some modern photos taken recently, to see how much the landscape has changed.
https://www.standard.co.uk/go/london/arts/london-art-nine-paintings-of-the-river-thames-you-have-to-see-a3900821.html
Fancy having a go? You could copy one of the famous paintings from the above examples, or try drawing your own. If you don't have oil pastels, don't worry, you can use pencils or even crayons. Just remember to use the shading technique and build up the colour. Have a look an example of how you might start:
https://www.youtube.com/watch?v=-VVIVM0bDXY