No1 The Thames goes up for sale for half the price of average UK home - but there's a catch

A 168-year-old building that has the address No1 The Thames holds a unique military history and is now up for sale. The military building where the nation was defended from during the First and Second World Wars could be yours for less than half the price of the average UK home.

The gun tower located at the mouth of the River Thames in Kent is being promoted by Estate agents Savills as a property with “a unique and peaceful position with far-reaching sea and coastal views".

Auctioneers expect the Martello tower-like building will fetch £150,000. They added the property, on a spit of land between the River Thames and River Medway, “is a first.”

The ex-army site is only accessible twice a day, at low tide via a causeway, and owners and guests will have to use a boat at any other time.

Auctioneers expect the Martello tower-like building will fetch £150,000. They added the property, on a spit of land between the River Thames and River Medway, “is a first.”

It was the last gun tower of its kind to be built, constructed to protect the nearby military dockyards against French invasion.

Anglo-French tensions ran high in the 1850s and the nation feared a naval attack. The tower guarded the key link between the Thames and Medway rivers, which led to Royal Navy Dockyards in Sheerness and Chatham.

However, artillery technology quickly improved and the construction became obsolete in the mid-19th century, almost immediately after it was completed.

By the end of the century it was transformed into a defence against raids by fast torpedo boats. Decades later it was altered again - new, quick-firing guns were added during World War I and World War II.

The property off the Isle of Grain, built in 1855 was decommissioned in 1956 and will go under the hammer on September 20 this year.

It is around four-and-a-half miles from the nearest train station of Swale but any potential buyer would need to spend a large amount to repair and return it to its former glory.

Savills Auctions Director Jeremy Lamb said the sale is rare adding: “There is always excitement when unusual lots come along as they have a special power to capture the imagination.

“We’ve had water towers and military sea forts in our sales in the past, but this gun tower is a first. A blank canvas with heaps of history and phenomenal sea views, not to mention its coveted No. 1 the Thames address.

“Historically, rare lots like this have seen significant interest in our auctions.

“Last summer the hammer came down on Bull Sand Fort in the Humber Estuary at nearly 10 times guide price after attracting bids from around the world and the year before that we auctioned a water tower in Essex which has since received permission for residential use and a chance to design a once in a life time property.”

A spokesperson described the potential buy as “atmospheric.”

They said: “The tower occupies a unique and peaceful position with far-reaching sea and coastal views. The village of Grain is approximately one mile to the west.

“The tower is atmospheric internally with a series of rooms, exposed brickwork and concrete.

"Of interest to developers and occupiers, the tower represents a unique opportunity with potential for alternative uses or development subject to the necessary consents.”