Spot the difference!

While we were waiting for Astrid to finish her ice cream outside the cathedral in Tours, we started noticing the differences between the two towers, which aren't immediately obvious.

Cathedrals are often built over hundreds of years, as architects, styles and techniques change, so this is quite normal. But the changes can also tell you a bit about the history of the building.

See how many you can spot. And which tower do you think is older?