It's time to open the vaults on something that many of us use every day – coins! There's some 29 billion coins in circulation, but how are they made and what engineering challenges are present in making so many shiny, tiny pieces of metal?

The Great Fire Trail: a free Time Hunters history walk around the City of London
1:02:38

Marina Ventura and The Micro-Gridders: Your Go... Designing A Grid of the Future
04:40

Marina Ventura and The Micro-Gridders: Energy Guzzlers
05:27