I may do a couple in January but then I’m going to be living abroad until May so I’m not able to do any walks until early Summer. Watch this space for more info!

Many thanks for the kind words Tom! So glad that you enjoyed the walk

I enjoyed an Urban Geology walk in the City of London with Ruth today. A great way to spend the afternoon, very interesting, highly recommended

Here’s a closeup of the slag concrete on the lower reaches of the Thames

It’s used for embankments on the Thames estuary too!

There’s info on this on Webb Yates’s website

For our Festival of Geology weekend we have three urban geology walks on Sunday 8th Nov 2026 👣 𝐖𝐀𝐋𝐊 𝟏 - Stones in the City with Mike Howgate 👣 𝐖𝐀𝐋𝐊 𝟐 - The Urban Geology of Battersea with Ruth Siddall & Diana Clements 👣 𝐖𝐀𝐋𝐊 𝟑 - The Evolution Garden at the Natural History Museum with Paul Kenrick

Sorry! I didn’t build this! 😂 I’m afraid I only know about the stones

Sorry, no I don’t. Stone is not that much heavier than concrete; structural concrete has a specific gravity of ~2.5 and I reckon larvikite is around 2.6

It’s obviously stronger than timber and fireproof. Post Grenfell, a timber structure is illegal. Stone will not grow back but there is a LOT of larvikite. Steel & concrete are also non-sustainable quarried materials but require many steps to process them from quarry to building. Stone has just one!

The building is constructed from beams of larvikite, a monzonite from southern Norway which is more familiar as decorative cladding because of its iridescent feldspars. However it has a compressive strength 3x that of concrete. This is the 1st building to use larvikite structurally in 100 years

Could this be the most important building in London this century? I think so! It’s a return to using stone structurally to build a 10 storey tower and hugely reducing the carbon impact of building. By Groupwork and Webb Yates engineers, Petra Heights on Finchley Road is monumental in so many ways 🧵

😘