Tower P has stood on Felixstowe seafront for 200 years.
Like the other 28 towers built on our coastline they are a reminder of the threat Napoleon once had on this country.
Most of the remaining towers are either private homes or stand derelict but Tower P will be open to the public on certain days after a refurbishment programme, paid for by Suffolk Coastal Council, Historic England and Bloor Homes.
The Towers were built at great expense and none of them was ever used in anger.
Over the years the towers have been used as customs houses, lifeboat stations, nuclear bunkers and homes of Coastwatch.
At 30 feet high and with walls that are 13 feet thick concrete they are virtually impregnable. If you want to imagine what life would have been like inside the towers, Touching the Tide have produced a virtual tour.
Click below to watch a report from ITV News Anglia's Kate Prout