My transatlantic journey included a connection at Heathrow.

Already at check-in at Václav Havel Airport I was given a leaflet with instructions on how to get from Terminal 3 to Terminal 5. After deplaning I started looking for the purple Terminal 5 signs. Buses between terminals run fairly frequently (roughly every 10 minutes). Along the way we passed through tunnels several times and stopped at traffic lights... After the obligatory security check at Terminal 5 I went to explore it. There are almost no smoking areas (compared to Prague where smoking is permitted in every other lounge/restaurant), but you'll find an enormous number of duty-free shops. There are plenty of seating and rest areas (chairs, armchairs, and loungers) and the view of the airport is breathtaking. The transfer to Terminal 5C is by underground (it's below ground level, comparable to Line M2 in Budapest). The ride takes a moment and then all that's left is finding the right gate. The cherry on top is the music playing in the toilets — Antonín Dvořák: Symphony No. 9.