One of Kent's most unusual properties – with the enviable address of No 1, The Thames – is back on the market.

For a cool guide price of £500,000 the abandoned Grain Tower Battery could be a possible nightclub, sports venue - or a seven-bedroom family home with a difference.

The Victorian building looked like being sold just over a year ago when the potential buyer put in an offer for £400,000.

However, the plug on the deal has just been pulled and last Friday the For Sale signs went up again after long delays in completing paperwork.

Nigel Day, from London-based River Homes estate agents, said: “It was simply taking too long. It’s too early to say what interest there will be, but it certainly has the novelty value.

Phrases like “genuine investment opportunity, “unique location” and “character property” would spring to mind.

“I did spend a bit of money making it habitable and did live there for a while. But I soon realised it was more of a bachelor pad”

But Mr Day, who is more used to handling luxury apartments and houseboats on the River Thames, said: “There is no point in deceiving people. It needs a lot of work doing on it.”

Mr Day is drawing up a revised property description of the 19th century concrete military installation to tempt clients.

It lies off the Isle of Grain where the River Medway meets the Thames estuary. At low tide it can be reached by a precarious causeway, but otherwise it is completely surrounded by water.

A firm grasp of tide tables is recommended because at high tide the only way in or out is by boat or helicopter.

It also does not have electricity or running water.

Mr Day said when it first went on his books last spring, it attracted a lot of interest.

It was bought by builder Simon Cooper about 12 years ago who had intended to convert it into a family home.

Mr Cooper said: “I did spend a bit of money making it habitable and did live there for a while. But I soon realised it was more of a bachelor pad.”

Estate agent Jonathan Hacker said the fort came on to their books by chance as Mr Cooper was working on one of their offices.

Mr Hacker said: It is one of the most unusual properties we have had. We are more used to dealing with house boats on the Thames. I think its main appeal was its potential.

“It went online and suddenly sparked amazing interest both in the media and with potential buyers.”