Beneath a railway bridge, Swiss artist Franziska Furter's "Mojo" (2012), a colorful concoction of magic amulets, hangs like a chandelier, moving and tinkling with the wind.

WSJ: Collecting: 'Art and the City' Show

Not to be outdone by these century bonds, Eurotunnel, the beleaguered company that operates the railway beneath the English Channel, is trying to tempt investors with a millennium's worth of profits.

ECONOMIST: From here to eternity

Beneath us was a railway line and in front of us, Circular Quay, the tourist hub of Sydney, from where quaint green and gold ferries plough their way across the harbour.

BBC: Subterranean Sydney

They came for a variety of reasons, including the amount of available space, particularly in the Bermondsey railway arches that support the London Overground (five of the six are housed beneath an arch).

BBC: London��s weekly beer pilgrimage