As you head towards the Town Gardens you are heading towards a new area of rock known as Purbeck Limestone.

Purbeck sits above Portland Stone and was created in a hot, semi-arid environment. The Portlandian Sea was on the retreat leaving a trail of lakes of brackish swamp and shallow lagoons behind it. The Jurassic Sea was drying up and the rocks in Town Garden were drying up as well. True marine shellfish started to disappear to be replaced by algae growths.

It's at this point, if any, that Swindon emerged from the sea. But not for long. A few millions years later, during the Cretaceous Period, the sea came back and the whole area was swamped again under another marine environment.

Walls of Ammonites

On the corner of The Quarries, set into a garden wall, you can see a series of local ammonites found in Swindon quarries. The largest, an ammonite called a Titanites giganteus, is 150 Million years old.

Ammonites were truly marine animals and would never have survived in Swindon during the Purbeck Period. The environment they lived in was always marine, warm and tropical.

Their fossils fail to show, however, how fragile their shells were. Separated by internal chambers their shells could be filled with gas to enable them to rise up and down in the water.

Ammonites in a wall at the Swindon Bowl.

More ammonites can be seen in the steps leading down to the Swindon Bowl in Town Gardens.

As you head into Town Gardens you are actually entering an old quarry which from the 17th century onwards yielded first Purbeck Limestone and than Portland Stone.

Purbeck Limestone, discovered just 5' below the surface in 1640, became massively in demand during the rebuilding of London after the Great Fire of 1666.

Not it seems for the rebuilding of monuments or churches but for paving stones. The Streets of London are in fact paved with Swindon Stone.

... standing opposite the Swindon Bowl take the steps on you left and turn right at the path at the top of the steps. Turn right on the next path and head towards Quarry Road. Turn left on Quarry Road and at the end of the road turn right on to Bath Road. At the mini roundabout at the end of Bath Road turn left and you'll find yourself back on Victoria Road.