Image copyright Jason Hawkes

Call me pedantic, but London City Island in the capital's Docklands is not really an island at all.

A bird's eye view reveals that it is actually a peninsula, caused by an oxbow bend in the River Lea, shortly before it flows into the Thames.

But before I go too far in pricking the balloon of the marketing team that invented the island concept, it is worth pointing out that whoever named the nearby Isle of Dogs had the same problem; that too is very definitely joined to the mainland.

That said, London City Island - as I shall agree to call it - is a remarkable, if expensive, development.

There is certainly lots of water here, although at low tide there is also quite a lot of mud.

Given that it is corralled by a loop in the river, it also has the appeal of a very individual and separate place.

Hayleigh O'Farrell, head of communications at Ballymore Developments, accepts it may not be a physical island, but says, "It's got that different, kind of island feel."

It also has truly excellent transport links.

After residents walk over the footbridge to the tube station, it is just a 20-minute ride into the very centre of London, according to Transport for London's journey planner.

Within a couple of years the 12-acre island will also be home to the English National Ballet (ENB), and the London Film School. The ENB will base its production facilities there, and stage rehearsals.

Lorries will be able to drive in and out to transport sets all over the world.

For that reason Sean Mulryan, the Irish billionaire behind the development, has described it as his "island of dance".

This is no dormitory suburb. When it is fully finished, it will be a place that some say will be a spectacle in its own right.

Once the site of a margarine factory, the 1,700 flats are being built in double-quick time.

Most of the units were prefabricated in a factory in Holland, and shipped to the UK, enabling the first phase to be finished in less than a year.

"They go up like Lego," says Ms O'Farrell. "It's one of the fastest-paced constructions to go up in London."

The design is modelled after the colourful apartment blocks typical of Manhattan or Chicago.

"They are super-bold colours - so each of the bricks really pops."

So what sort of person will be living here? Given the big gym on-site, one imagines the residents being highly athletic, ballet aficionados who are pretty wealthy. The kind that spend their weekends at Glyndebourne perhaps.

"They've clearly set out to provide a very sophisticated product for what they hope will be a sophisticated - and wealthy - clientele," says property commentator Henry Pryor.

He believes most buyers will be asking the Bank of Mum and Dad for support.

"If asked to help their kids afford these kind of properties, they're going to say, 'Look, it's something that we can justify because not only does it work for you, but darling, we can come and stay there too.'"

However, the developers point out that there are 119 affordable properties in the development, around 7% of the total.

They also say that among the 650 people who've already moved in are artists, writers and animators. Presumably many of the others are wealthy bankers who work at nearby Canary Wharf, just four minutes away by tube.

"It is a young profile, a lot of people working in the area," says Ms O'Farrell.

"What really surprised us is that people have moved from all over London: 10% I think were from Battersea, and there are people who moved from Chelsea and from Tower Hamlets."

By any definition, you have to be wealthy to buy here.

Prices start at £495,000 for a one bedroom flat, rising to just over £1m.

On that basis, anyone putting down a 25% deposit of £124,000 would need to earn £80,000 to £90,000 a year to afford the mortgage.

In a market where central London house prices have fallen by 20% in a year, some experts believe such prices are now too high.

"The question is: will it suffer the same issues and challenges that so many of the shiny developments strung out along the river from Putney Bridge to Greenwich are suffering from now? Are there people who can afford to pay the prices that are being sought here?" says Mr Pryor.

He points out that many of the foreign buyers that used to inflate demand for London properties have now disappeared.

"The prices are clearly going to be incredibly challenging in this market, because they appear to be priced for buyers from 18 months ago."

Ballymore insists the flats are not over-priced.

Since launching in 2014, it says 85% of the properties have already been sold.

Ballymore is about to launch its next development nearby, close to Trinity Buoy Wharf. With its Victorian lighthouse, and surviving brickwork from old shipyards, this too is likely to become an interesting place to live - as long as it does not spoil the area's wonderful industrial heritage.

From both places the views along the river are spectacular.

"As developments go, this has been incredibly well-thought-through, and deserves every expectation that it will succeed," says Mr Pryor.

But if you want to live on a real island, London City Island may not be the place for you.