Another easy destination from London is Poland. British Airways will get you to Warsaw Chopin airport (closest to the city centre; a 30-minute bus ride) in 2.5 hours and once there, just let the fun begin.
Warsaw is a city with a beautiful new old town centre, lots of history and amazing food. It can get a bit cold though so make sure you put on a couple more layers.
I have summarised my favourite destinations in Warsaw in the sketchnote below including places to see, best restaurants in town to try local cuisine and my favourite shot recipe!
PS) Also I paid 4 pounds for 8 shots!