You may be standing on the original Fosse Way, the Roman road that stretches south as far as Exeter and north as far as Lincoln. The black and white building in front of you is the Guildhall, dating from the 14th Century.

Some of the stones in the Guildhall walls are 400 million years old.

It was built for the Corpus Christi gild and was one of the most important buildings in the city. Look up at the roof, which is made from Swithland Slate. This was quarried just a few miles away, but was formed in Precambrian times (580 million years ago).

On the base of the Guildhall, the yellow Millstone grit is 350 million years old. The pinky/grey diorites are probably 400 million years old.