One thing I like to do when traveling is to visit interesting flight-related museums. My favourite so far is Duxford Imperial War Museum near Cambridge in the UK. On one RTW trip I was "transiting" through London with an early morning arrival into LGW (from DFW) and then an evening departure from LHR (to SIN). So I rented a car and drove around the M25, through the Dartford tunnel and up to Duxford where I spent the day. It was a windy, cold, rainy February day, and I pretty much had the whole p[lace to myself, except for a few fellows restoring a Spitfire in one of the hangers.
I could spend as much time as I wanted walking through Concorde 001 (the flight test aircraft). I was disappointed that the static display VC10 was closed that day, but did get back (with my entire family) a few years later on a more pleasant summer day when the VC10 was open for inspection.
What flight or travel-related museums have other members found interesting and why?