'It's like being in Palermo,' ventured Russell, my partner, as he pushed open the window, welcoming in the roar of traffic below. Our room, fuggy with fumes, could use some fresh air. As we lay tipsy on the bed and the sirens wailed around us, I had to remember that we were actually spending the first night of our holiday in Stratford, not Sicily.
Can anywhere become interesting if the right mindset is applied? When I glimpsed a leaflet in a north London park giving details of London's 'Capital Ring,' walking route, I was curious. Inside, a map outlined the 78-mile circular route through Woolwich, Crystal Palace, Wimbledon, Richmond, Harrow-on-the-Hill, Stoke Newington, Highgate and Hackney Wick.
We formed a plan: to walk the Ring in a week, 12 miles a day, with each night's accommodation - a pre-booked jumble of B&Bs, chain hotels and opulent riverside palaces - as near as possible to the route; to begin and end in Highgate (geographically convenient); and to raise money for the charity Walk Once More (www.walkoncemore.org), set up by a friend with a spinal cord injury.
Rucksacks bulging, a week or so later we strode into the glare of the Saturday morning sun, relishing no airport hassles, no glum faces and, thrillingly, no half-hearted compulsion to extract historical interest from an unknown city. This adventure would, we decided grandly, give perspective to our lives in the great metropolis. (Sipping a pint in Balham, halfway round, we watched sharp-suited commuters, so upright and serious, with the fascination normally reserved for an indigenous people.)
And from the start in Highgate, the Ring, a well-signposted route that meanders through mostly green spaces, threw up immediate delights, despite the hum of traffic never being far away. Near the disused platform of the former Crouch End station, a giant sculpture leapt out of the wall. It was a 'spriggen', a local goblin rumoured to steal human babies.
Other little-known sights slid past: ragged Abney Park Cemetery in Stoke Newington, with its 300,000 graves and deep earthy smell; a flotilla of painted canal boats at Springfield Marina in the Lee Valley; kestrels hovering over Walthamstow Nature Reserve, the last surviving marshlands in London.
We soon learnt a few tricks: our first lunch, of smoked haddock kedgeree and chicken pie, was delicious, but that afternoon's walk was, groaned Russell, 'like being pregnant'. And too much booze was a no-no: a red-wine-fuelled first night in Stratford made the second stretch, down to Woolwich, initially rather bleak. But, as we strolled along the River Lee that Sunday morning, we became imaginers of other people's lives. Why was that man slumped on a bollard by the lock, head in hands? What lurked in those floating bin bags? Whose was the sodden black hoodie on the bank?
Solo rowers swished by, fishermen with dreads smoked reefers to loud reggae, and a gospel choir rang out behind a stretch of graffiti-ed wall. I thought about the diversity of life in this city.
'So, we're walking on shit,' said my brother, who had joined us for a day, as the smell wafted on the breeze. This was the Greenway, a brambly recreational footpath from Hackney to Beckton, built over six miles of pipes pumping 100 million gallons of sewage a day.
The path offered a vantage point over the low-level, work-in-progress Olympic Park, which looked for a moment like a civilisation after extinction: cranes rose over warehouses, while skips and tractors squatted on mud, the silence punctured only by the bleep of a lone truck traversing tips and scrapyards. Yet, along this unlikely stretch we came upon gems such as the Abbey Mills Pumping Station - a Grade II-listed oriental 'palace', opened in 1868 and known, delightfully, as the 'Temple of Sewage'.
That afternoon the Woolwich foot tunnel, with its stench of urine, ejected us south of the river, where the awe-inspiring metal of the Thames Barrier gleamed in hazy sunshine.
Our trek took us on through south-east London, a blur of palaces, gardens and commons, including Charlton House, a splendid Jacobean pile near Blackheath, derelict Severndroog Castle, built in 1784 and the highest point of the Ring (404ft), and windswept Beckenham Place. Most spectacular, however, was the medieval royal residence and Art Deco home that is Eltham Palace.
By the third day, after a sleepless night in a boutique hotel near Blackheath, aches and pains had blossomed: blisters itched under the skin of our feet; I had been stung by a wasp; shoulders and lower backs throbbed. Yet nothing was more perspective-inducing than seeing roadside bouquets at regular intervals, heartfelt memorials so easy to ignore in the flapping urgency of our lives: 'Bruv - Ben - Cuz,' read one on Southend Road. 'Don't mourn for me. I'm still here, though you don't see.'
And it was while considering this, sunlight filtering through the hornbeams, rattle of woodpeckers in the distance, that I realised I had nothing on my mind. The drum of anxieties had stopped beating. All you have to do is follow the road ahead, I thought.
But then the weather turned. On the fourth day, as we left the charmingly anachronistic Bromley Court Hotel, torrents of rain swept across south London. Under funereal skies we forged ahead, rain pouring down into the shadowy depths of the wood, gusts rattling the crowns of yellow-leaved oaks. Clocking up 14 miles in four hours, we could only glimpse the dripping dinosaur sculptures in Crystal Palace Park, its landscaped waterfall tropical in the mist, before taking shelter under the green steel girders of the crumbling cafe.
And, after paths on Biggin Wood and Streatham Common had turned into mudslides, we were greeted by our B&B owner with the heavenly words: 'I've got flapjacks in the oven and the kettle's on.' How unexpected it is, I thought, stewing in the bath later, to holiday in London with your needs reduced to the basics: food, water and rest.
The remainder of our journey across south-west London chomped through Wimbledon Common, Putney Heath and Richmond Park, where screeching parakeets danced round the pines.
Most nights we chose simple accommodation, but a must-stay was the elegant Petersham Hotel, with its terrace overlooking cattle grazing in the meadows by the Thames. Early next morning, shrouded in mist with its clatter of boats, Richmond Bridge brought to mind Venice, as silhouetted cafe owners unstacked chairs with choreographed precision. Eerier still was nearby Isleworth Ait, an island in the Thames which, with the tide out and barges beached on banks, was as other-worldly as some Mississippi backwater.
Six days after setting off, we'd hiked full circle back to north-west London. Here the route was almost empty, apart from three middle-aged ladies doing it in stages: 'We're too busy to do it all in one go.'
Drifting through suburbia, I realised it was the quiet details that had endured in my memory: the former East London slagheap renamed Beckton Alps; the all-you-can-eat Chinese restaurant in Charlton, where we were warned we'd have to finish one course in its entirety before being allowed another; and drab Brent Reservoir, in Victorian times a fashionable resort called the Welsh Harp.
Our last stop was Harrow-on-the-Hill, awash with schoolboys in boaters and teachers with mortar boards yet, we discovered, once a site of pagan worship. 'At least,' said Russell after dinner, 'its restaurants have made it into the 1970s.' Black steak with shallot sauce, anyone?
Highgate's hilly copses - or Gravel Pit Woods - provided a dramatic climax to the trek, and as we collapsed with a pint I was reminded of an information board back in Beckenham Park: 'Walking in parks and woodland,' it told us, 'is a relaxing way of coping with the demands of modern life.' My father, our final guest walker, sipped his restorative shandy and agreed: 'Solvitur ambulando,' he announced. 'Things are worked out by walking.'
Essentials
For route information and to order free maps, see walklondon.org.uk or call 870 240 6094.
Hotels: Express by Holiday Inn, Stratford, doubles from £89 (hiexpress.co.uk; 0870 400 9670); Best Western's Bromley Court Hotel, from £89 (020 8461 8600; bw-bromleycourthotel.co.uk); onesixtwo, Blackheath, from £80 (020 8465 5444; onesixtwo.co.uk); 52 Becmead Avenue , Streatham, from £70 (020 8696 0107; 52becmeadavenue.co.uk); the Petersham, Richmond, from £170 (020 8939 1010; petershamhotel.co.uk); the Old Etonian, Harrow, from £75 (020 8422 8482; oldetonian.com)
