A tour like this is all about the guide - and ours, a Portuguese Parisien named Pablo, really was the best.
A fascinating tour through the heart of the French Revolution, which lots of background history brought to life to Pablo. We were amazed to find out at the end that this was the first time he'd given this tour - he really was a natural!
Definitely worth doing, but book a few days ahead and call the company who run the tours to confirm - we booked the night before through Viator and our booking hadn't reached the tour company, or our guide. We missed the start and he had to run back to get us - all done with great humour but it was a bit annoying for us, Pablo and the rest of the group!
Anyway, a great few hours and thoroughly recommended.