A landmark building that is a familiar sight to passengers arriving on the ferry - but less visible from dry land - is up for sale.

Harold Tower, off Fort Anne Road, Douglas, would constitute the ultimate upgrade and you could rest assured no one else would have a home quite like it.

But it will cost you the best part of £4 million.

Three estate agencies have been engaged by the local family that owns it. It has undergone an extensive renovation, between 2009-2012.

Shane Magee, chairman of Chrystals, which is handling the sale along with Cowley Groves, and London firm Knight Frank, said it was clearly a ’labour of love’ for the current owners, who previously lived there.

The owners wish to remain private, but it is understood they still live in the island.

Mr Magee took the Isle of Man Examiner on a tour of the unique home, which dates back to 1833, and is set in three acres of secluded gardens.

’You have the whole package, of quality, of history, of convenient location, of privacy,’ he said.

With a £3,950,000 price-tag, you would expect something special and it does not disappoint.

Should J.K. Rowling be looking for an inspirational place to put her writing desk, then the octagonal office in the turret, with its breath-taking views across Douglas Bay, might just swing it for her.

If she then wanted to watch one of the movie versions of her Harry Potter books, the home cinema room - that could just as easily be turned into another bedroom - might be just what she’s looking for.

For those who have happy memories of big nights at the Palace Lido, the flooring in the reception and drawing room will appeal - it’s the restored and reconditioned woodblock from the famous venue!

In plain figures, there are eight bedrooms, four reception rooms, three bathrooms and two double garages. Inevitably, there is an impressive wine cellar. Plus, a roof terrace, the swimming pool that can be covered over, the coach house by the entrance and a modern cottage also within the grounds.

Everything has been upgraded to meet every modern expectation.

If you get bored at looking out to sea, you just turn slightly and admire Snaefell and its surrounds. Or take a stroll down the private pathway to head to the harbourside.

The history of the building, that is known, is intriguing. It is thought it was named after King Harold, possibly as a nod to its previous status as part of the Nunnery grounds.

The artist John Martin is believed to painted Plains of Heaven while he was resident there in 1851-53. During the Second World War, it was owned by Cissy Milne, who also owned the Waverley Hotel.

When the government commandeered the seafront hotel to use as part of an internment camp, she turned Harold Tower into a hotel.

It became a true home once again after war and, when relatives sailed to the Isle of Man, Cissy could be seen in a tower window, waving a pillow case as the ferry approached!

Cannons dotted around in the grounds are the real deal. Now decommissioned, they were once used at sea - a previous owner used to manufacture cannons for the Navy.

The same family has a coat of arms at the back, with a crest that translates to ’Better by discussions than by war’.

At the front of the house can be seen the original coats of arms, restored and painted with real gold leaf.

Cowley Groves director Mark Canty said: ’There is no question that Harold Tower is unique in every way possible.

’The sheer care and attention to detail that the current owners have put into the interior design is unparalleled and above all else, it is a castle steeped in history.

’It is incredibly rare to have the privilege of such a listing.’

Estate agents are not known for understatement, but in the case of Harold Tower, it is not hyperbole. I’m off to buy a lottery ticket.

www.haroldtower.com