The Barclay's Bank HQ in Canary Wharf (also known as One Churchill Place) has got a few new residents as of this week.
There's a money spider (obviously), a few ladybirds, plenty of greenfly and some grasshoppers; and they're all making themselves at home in the world's tallest man-made nature reserve on the roof of Britain's seventh tallest office block.
The garden was designed by the fantastically named Dusty Gedge, a keen 'twitcher' who really wants to attract the rare the black redstart to the 150 metre-high (500ft) Barclays roof.
"I am pretty certain that they will be here by next spring," says Dusty. "We know that there is a mating pair nearby and in the 1980s there were 14 pairs on the Isle of Dogs."
According to Dusty there are also "rare wasp-eating spiders" on another roof nearby, wehich frankly scares the crap out of us. But we can see the point of the 'green roof' which was designed to replicate "the ecological conditions found on the old building sites - until recently, common throughout London, but now increasingly rare."
And, if you beleive Dusty, this is just the beginning:
Vast areas of London's roofs could be greened. You could have house sparrows, bats, birch forests, wetlands, anything you want.