Maunsell sea forts. Red sands sea forts Thames estuary. They are now abandoned Stock Photo - Alamy
Visiting the Red Sands Sea Fort — Russ Garrett
GitHub - gyowanny/redsand: User authentication API. The "red sand" is a reference to the Red Sands fort also known as Maunsell Army Sea Forts (http://www.ecastles.co.uk/armyforts.html)