www.pillboxesuk.co.uk

Anchor text: British Invasion Defences

Wikipedia: Operation Sea Lion

Anchor text: UK Pillbox, Pillboxes, Bunkers, Anti-tank traps and other Anti-Invasion Defences built in World War 2

Wikipedia: East Anglia

Anchor text: British Invasion Defences

Wikipedia: Battle of Britain

Anchor text: UK Invasion Defence Remains

Wikipedia: Taunton Stop Line

Anchor text: UK World War 2 Invasion Defences

Wikipedia: GHQ Line

Wikipedia: Auxiliary Units

Anchor text: British World War 2 Fortifications

Wikipedia: Blockhouse

Anchor text: UK Pillboxes and Invasion Defence Remains.

Wikipedia: Outer London Defence Ring

Anchor text: UK Anti-Invasion Defences

Wikipedia: Northover Projector

Anchor text: Pillboxesuk.co.uk

Wikipedia: British anti-invasion preparations of the Second World War