Architecture
Take a busman's holiday with an architect. If your wife / husband is an architect, you could set off on a world tour with the aim of seeing all the architectural greats as well as having an enjoyable holiday at the same time; sort of giving your trip a different focus (instead of the usual wine, food and self-indulgence). However, if your partner is inconveniently an accountant or a dental surgeon, you won't be wanting a busman's holiday. Never fear. All is not lost.
Harry Seidler's The Grand Tour: Travelling the World with an Architect's Eye will come to your rescue. Clutching this little volume, you can confidently visit Santa Maria della Salute in Venice, The GUM Department Store in Moscow, Angkor Thom in Cambodia, the Copan Building in Sao Paolo, Frank Lloyd Wright's Kaufman House, or the Pont du Gard in Nimes. Just enough detail to whet your appetite and drag you to far flung corners of the earth.