Watching live camera footage of different cities over the world seems like a relaxing activity to me. Can't recommend any particular website, earthcam.com just pops up when you Google it up so I tend to use that one (redirects you to places).
Also, learning some geography by looking at interesting relief features in en-gb.topographic-map.com -> The World, and finding those features in Wikipedia to learn more about them. Bonus points if you check on satellite imagery or pictures taken by visitors of places through stuff like Google Earth. As a Spaniard, I'll never get tired of dissing on the Great European Plain