1. So my new thing here is the #10tweetadventure - exploring corners of history or landscape, but told in no more than 10 tweets. Today, for @FingerpostFri #FingerpostFriday, let's start with the source of the River Thames. Except… it isn't. 2. For one thing, the site in Trewsbury Meadow has totally dried up - fair enough, it was always seasonal. But half a mile downstream is Lyd Well, in the area marked on old maps as Thames Head. But alas this was bone dry today too.

Today I'm embarking on another London walking expedition, but less bonkers than the #londonfogg adventure. Join me on a 6-mile walk as I listen to the echoes of a Saxon-era cult, and learn about some literary legends, lost spas… and a walrus. At 11am, I give you: #pancrasday Today, 12 May, is the feast of Saint Pancras, a little-known saint whose name is writ large in London, and commemorated in various UK churches. He was a 3rd century Turkish-born Roman who converted to Christianity & was beheaded c.304AD, perhaps by emperor Diocletian. #pancrasday

It's 150 years this year since Jules Verne published Around the World in Eighty Days. Today I shall embark on my own voyage of homage, on foot, visiting places related in some way to every country Phileas Fogg went to. But the twist is it's all in central London. #londonfogg 🧵 So at 10am I bring you: Around the World in Eight Hours. I blame @politic_animal for catalysing this misadventure with his #bus24 and #train24 voyages. Please follow this thread or #londonfogg to watch my knees give out over 20+ miles of London walking…