At the end of the tour, we walk up and down the Merchants' Bridge.
Built of stone in 1325, it is now home to 32 beautiful historic houses.
Now, just before 6:00 p.m., we quickly enter the House of Foundations.
There's an exhibition on the history of the bridge here.
Incredibly, there's even a cellar in the bridge pier.
It's exciting to walk through the old house; the floorboards creak with every step.
From the second floor, we look out over the bridge.
Here's our full tour