The evolution of Scarborough

Follow the castle wall until you reach some steps. After the first flight, carry straight on, the second flight takes you to the right, then once you've reached the tarmac path, turn left.

Then you'll find yet more steps down toward the Old Harbour. Turn right, and after a short distance turn right on to Quay Street.

As you near the end of the path around the castle wall you'll see a light grey wall. Closer inspection will show this wall is rich in fossils. These rocks, formed around 150 million years ago, are a hard limestone that make a very sound building material

Much of the castle walls are built from fossil rich limestone

On closer inspection, loads of fossils, some quite large, can be seen embedded in the rock including: Oysters, bivalves, and sea snails. Look even closer and you can see that the rock is made of tiny spherical balls of calcite.

These were formed as they rolled around on the sea bed. The same process still goes on in the Bahamas, so geologists are confident that when these rocks were formed the area enjoyed a much warmer climate.

Britain's coastline continues to change shape, and sometimes quite rapidly. At Scarborough the coast is quite soft, although not as soft as further south towards Bridlington.

The coastal erosion is quite rapid with significant changes to the coastline taking place in living memory. So in a geological time scale we wouldn't have to go far back for the coastline to be completely unrecognizable.

The red roofs of the 1930s suburban expansion of Scarborough

If you look across the bay from here you can clearly see the treeless dip in the south cliff where the Holbeck hall landslip occurred. Just to the right of that is the South Bay pool landslide, and despite the work to landscape the site, it's still possible to see where the landslide affected the Spa area.

In an attempt to try and protect Scarborough's coastline, sea defences are being built from concrete and Larvikite. This is a dark grey, very hard igneous rock from Larvik in Norway.

The headland provides a good view across the town, and it's possible to see how Scarborough has developed. Directly below the headland are the red roofed buildings of the harbour-side quarter. This would have been the heart of the medieval town.

With some areas of cliff it's possible to see where land has broken away at some point

The area up toward the market hall is the Old Borough planned town. Beyond that is the New Borough. This stretches to the right towards the Multi-storey car park.

Further still, as the roofs turn grey, is the Victorian development of the town. The area below South Cliff experienced huge expansion in the 1820s. Then on the far right of the town, where roofs turn red again, you can see the more suburban 1930s development.