The Park Side: How much for a green view in London?

Prestigious and protected, the capital's garden squares are bordered by some of its most desirable homes. But exactly how much of a premium do these properties command?

The former home of the late Princess Diana's aunt - a Grade I-listed affair with one of the biggest private gardens in Regent's Park - has just come up for sale sporting an asking price of £11.5m.

With 232 acres of completely private land, a Grade II* listed Georgian country house, a famous polo club and some serious provenance, Woolmers Park Estate in Hertfordshire is what you'd call "the whole…