On almost certainly the last warm, sunny day until next spring my mum and I met Tivoli in Chatham for its Heritage Open Days festival, some of which involved elegant Thames Sailing Barges. I've wanted to go on one of these ever since I first saw them in the Blackwater aeons ago. We weren't organised enough to get a trip on one, but we did get to go on board. I adore the intricate design of boat interiors - how no space is wasted and everything fits together perfectly like one of those 3D interlocking wooden puzzles. I was fascinated to see how parts of the structure lift off so that cargo can be loaded. As tidy, elegant and satisfying as the nine times table, which we overheard someone explaining to a companion in Rochester High Street a bit later.

Up at the castle, the support bands for UB40 were playing in a much-deferred gig that Tivoli and I, months ago, were planning to go to. We didn't, but we did come across our adolescent selves dancing down Boley Hill and gave them a smile.

Most of the rest of today's 3D puzzle is here.