I've already walked most of the Circle line while walking other lines: I walked from Aldgate to Baker Street on the Metropolitan line, Edgware Road to Baker Street on the Hammersmith & City line, and High Street Kensington to Edgware Road and Gloucester Road to Tower Hill on the District line. That leaves just two little corners of track that are exclusively used by the Circle line: Aldgate to Tower Hill and Gloucester Road to High Street Kensington.
To save time, I thought I'd slip them in along with my walk on the Waterloo & City line. Strictly speaking, I should be walking the Waterloo & City line after the Northern line, as I'm supposed to be walking these lines in chronological order, but it made much more sense to stick all these little, central-London walks together on the same day, and they go well together. For the record, the Circle line was finally completed on , though the first section of what we now know as the Circle was actually the High Street Kensington to Gloucester Road section, which opened on . I'll leave it up to others to debate which came first, the District or the Circle, and instead I'll stick to the walking...
Aldgate to Tower Hill
Come to think of it, I should have walked this leg the other way round, having walked anti-clockwise round the Circle line on my Metropolitan and west-east District line walks... but I'm never that clear-headed first thing in the morning, so I went for the direction that I'd written down. Still, it doesn't really matter, because whichever way you do this walk, it's a good one. The theme of this leg is modern architecture, and it takes in two of the most famous examples of mould-breaking design to be found in any city in the world. One example, the Gherkin, dominates the London skyline, while the other, the Lloyd's Building, is all but hidden from view until you stumble on it, but both of them have played a major part in dragging London into the modern age.
But we're jumping the gun a bit, because the walk starts at Aldgate station, the place where I started my tubewalk a little over a month ago. Around the corner from St Botolph's Church is Mitre Square, the scene of the murder of Catherine Eddowes by Jack the Ripper back on . This was the most western of the Ripper's five murders, and was the only one in the City of London. This murder, the fourth, happened on the same night as the third murder – Elizabeth Stride was found earlier in the night just southeast of Aldgate East station, in what is now called Henriques Street. The Mitre Square murder took place in the southern corner of the square, which is now occupied by a flower bed, a handful of benches and the gateway to a school-yard.
On a slightly cheerier note, one of my favourite London buildings lies just along Bury Street. The Gherkin, or St Mary Axe (to give it its official title), needs little introduction, with its distinctive curved shape protruding into the sky. Walking around the bottom of skyscrapers is always an interesting process, and the Gherkin is no exception, though on a sunny day, it's easy to be blinded by reflections from the thousands of gleaming windows. It's a toss-up between the Gherkin and the BT Tower for my favourite London building; I'll be visiting the latter on my Victoria line walk from Brixton to King's Cross St Pancras, and I'm already looking forward to it.
From the Gherkin it's a short hop to the Lloyd's Building, another seminal London sight. Built between 1978 and 1986, this 'inside-out' building has its stairs, lifts and pipes on the outside, leaving an uncluttered and open space inside. The twelve glass lifts that run up and down the outside were the first of their kind in the UK, and 22 years of weathering haven't dimmed the inventiveness of the design.
The route southeast towards Tower Hill continues with glinting glass skyscrapers towering over more traditional buildings, like Fenchurch station and St Olave's Church, before we reach the bulk of Trinity House, overlooking a little park next to Tower Hill. The view over the Tower of London is delightful here, and Tower Hill station is just over the road, underneath a popular viewpoint of the Tower that's as interesting for its tourist activity as it is for the view. It's a great way to finish off a treasure trove of architecture, taking us all the way from the four-year-old Gherkin to the 930-year-old Tower.
Gloucester Road to High Street Kensington
The walk from Gloucester Road to High Street Kensington is – like all walks through Kensington – a catalogue of exclusive and extravagant residences. However, there is one thing that differentiates this walk from the others in Kensington, and I didn't even know it was there until I stumbled on it. Just off Launceston Place, stretching to the east and west, lies Kynance Mews, and after the imposing terraces of Kensington, these mews are a breath of fresh air. The western side is particularly beautiful, and it is obviously a source of great pride to those lucky enough to live in it, because the houses are all painted different colours, there are loads of luscious plants and shrubs growing in pots along the road (with some houses smothered in gorgeous greenery), and even though you're in the middle of a city, there's a definite back-country feel to the road. The walk is worth doing for these mews alone.
A bonus is the imposing Christ Church, just to the north of the mews, which is best seen from Victoria Road (you can reach the road via a small set of steps on the right as you walk down the mews). Walking up Victoria Road and into St Alban's Grove, the mansion blocks that characterise so much of Kensington reappear with a vengeance, and the architecture continues in this vein until Kensington Square, a surprisingly quiet and leafy square given its proximity to Kensington High Street, which is just to the north, on the other side of the Barkers Building.
As you walk along Derry Street to the high street, look up and to your left, and you'll see the greenery of the Kensington Roof Gardens on top of the former Derry and Toms building. This is the largest roof garden in Europe, and although you can access them from Derry Street, they are not open to the public (though you can book them for private functions). Kensington High Street station is just along the high street, buried deep in a shopping centre and away from all the noise.