When I went in to wake up Mr Bunches and Mr F yesterday morning, this was the scene:
That red/yellow/blue castle there is in fact Notre Dame cathedral. Mr Bunches has been watching The Hunchback of Notre Dame more or less continuously for the last few weeks, and has taught himself to build cathedrals as a result.
(He's advancing. Previously, he was hooked on Hercules and we spent a lot of time building Greek stuff. Now, he's up to the Middle Ages.)