Blisworth Limestone Formation relationship to the Jurassic ridge, to the west of Peterborough. (BGS sheet 157) Around Towcester it reaches a thickness of 9m. (Hains & Horton p. 85) Blisworth limestone is used as a building material, in particular as blocks of stone. Lilford Hall in Northamptonshire is made from Blisworth limestone. Blisworth Limestone Formation The Blisworth Limestone Formation is a geological formation primarily consisting of limestone deposited during the Bathonian stage of the Middle Jurassic, found in the Jurassic ridge which extends north and south through England. It was laid down in the shallows of the Jurassic sea and is part of
Riqueval Tunnel Riqueval Tunnel The Riqueval Tunnel is a -long tunnel on the St Quentin Canal, close to the commune of Bellicourt, in the department of Aisne, France. It connects Bellicourt with Bony. It was constructed as part of the St Quentin Canal between 1801 and 1810, on the orders of Napoleon. The tunnel remains in use, and can be traversed using a chain boat. Along with the Mauvages tunnel, on the Marne–Rhine Canal, it is one of the last locations in the world where a system of chain towing is still in operation. It was the longest tunnel in the world