So the last villa ever to be built on Mustique is finally finished and available for rent, and what a puzzling addition to the island’s landscape it makes.

First there’s its name: Sienna [sic], presumably a tribute to Sienna Miller. But wait! Its style is unmistakably Italianate – Palladian, it has to be said, and therefore redolent of the Veneto rather than Tuscany. Though even so one cannot help suspect its owners were channelling memories of Siena when they decided to christen it.

Of course architecture is a matter of taste. And actually its architect, Julian Bannerman, creator of the yet to be built British Memorial Garden to the victims of 9/11 in New York, has a portfolio of laudable historically informed projects to his name (at Waddesdon Manor, Sydmonton Court and Arundel Castle). None lovelier or more inventive, to my eye, than the Antler Temple (illustrated below) that stands in the Walled Garden at Houghton Hall in Norfolk, once home of Robert Walpole, Britain’s first prime minister and the man who invented the national debt.

No doubt Sienna – an exercise in “unadulterated luxury”, runs the press release – is a glorious place to stay, with its two swimming pools, “swim-in grotto”, gym, media room and “spectacular water features”. (Mustique may lack groundwater, but at least it has a desalination plant now.) But it is a shame that the island’s last hurrah was not more of a homage to Oliver Messel, the marvellously inventive designer of its original villas  – which combined a sort of 18th-century neo-Palladian sensibility with Caribbean gingerbread styling and theatrical pragmatism – so creating what you might call the island’s vernacular.