In order to walk the walk as well as talk the talk, Londonist took its own advice and spent much of the hottest June day since 1976 standing in a tunnel in Rotherhithe.
The tunnel in question is of course Brunel's Thames Tunnel, the earliest stretch of Tube tunnel and the first tunnel to pass under a river. As part of Architecture Week, guided tours are being taken through part of this international engineering landmark, and since we're spending an increasing amount of our leisure time underground, it was hard to resist.
The 1200 ft tunnel connects Wapping and Rotherhithe. It was started in 1825, took 18 years to complete, and was originally conceived as a foot tunnel (a ramp to allow horse-drawn carriages to enter was also part of the original design, but never realised), Brunel's achievement now carries the East London Line under the river. However - and this is where the Thames Tunnel stands head and shoulders over London's other tunnels - it also for a time served as an underground shopping arcade, and is thus lined with 64 very fine stone arches.
At Rotherhithe station, tour parties link up with guides from the nearby Brunel Engine House Museum, who then flesh out the story of the awful struggle to build the tunnel - an extraordinary tale of determination, revolutionary and (quite literally) groundbreaking technology, floods, inundations, quicksand, irruptions, and fires. Then it's into the tunnel.
In order to build the tunnel, two wide brick-lined shafts were sunk, one in Wapping and one in Rotherhithe, to a depth of more than 60 feet. These remarkable shafts are still in place, and serve as the stairwells and lift shafts of Wapping and Rotherhithe Tube stations.
At platform level, it's onto a train. You don't actually get to walk down an operational Tube tunnel - that might be a wee bit dangerous. Instead, the Architecture Week arrangement involves all the tunnel lighting (usually only used for maintenance) being switched on, and trains carrying parties move extra slowly through the Brunel section. So you get a far better view than you would from a normal train.
And it is a wonderful experience - rather eerie, in fact. The slow progression of arches, with their classical stonework, feels more like something from a Roman catacomb than from the London Underground. The harsh industrial lighting only adds to the effect. Despite the lights and the trains and the noise, it is quite easy to imagine the cries of the hawkers in a different age.
It's also remarkable that after 160 years of constant use - more than half of which was taken with carrying trains, something the tunnel was not designed for - it's in such remarkably good shape.
In short, this is an absolutely must-see event for London. With plans afoot to extend the East London Line over the latter half of this decade, which will involve its closure for a time, it's not easy to imagine when there might be another opportunity to see this tunnel up close - although once the upgrade is completed in 2010, the Engine House Museum may well have relocated into one of Brunel's shafts in a shiny new visitor centre.
Tickets cost £5. Meet at Rotherhithe Tube ticket hall on 25 or 26 June at 13:00, 14:00, 15:00 or 16:00. You'll also need a Zone 1&2 Travelcard.
If you find this sort of thing interesting, and who can blame you, then go and have a quick browse of the wealth of info at the wonderful Subterranea Britannica.