Last Sunday we had breakfast at the Café Madeira beneath the viaduct beside the Albert Embankment. I tucked into smoked salmon and scambled egg on foccacia - a bargain at £3.50. Everybody else seemed to be Portuguese. Respectable, decent, hat-wearing folk chatted convivially beneath big wall-mounted LCD screens. A bakery next door turns out dozens of reasonably-priced and tasty-looking Portuguese specialities. Further down the viaduct there's a gay gym, some clubs and several bars, all part of 'Voho' the Vauxhall 'gay village'.

There's even art underneath the arches. Not far from the tourist disappointment that is the Lambeth Walk, the once grand Lambeth Ragged School has been sliced through by the railway. It was built by Henry Benjamin Hanbury Beaufoy FRS in 1851 as a memorial to his wife. Ragged Schools educated 'about 800 children' At the school's opening, Lord Ashley portentously declared that 'there is no reason whatever why Lambeth should not rescue itself from the present disgraceful opprobrium which attaches to it.'

The gallery was founded with high-minded ambition of the kind the ragged school's founder would recognise. It aims to “fill a niche between the institution, the commercial and the ‘alternative’”.  It isn't exactly welcoming from the outside. In trepidation we pushed the buzzer beside a blank door set into a high wall - but the people inside couldn't have been nicer or more friendly.

There was an unexpectedly warm welcome at nearby Southbank House too. You can't help being struck by the fabulous Victorian building in Black Prince Road, all ornamented terracotta and glazed tilework set into the window ledges. A frieze over the doorway is one clue to the office block's distinguished past. If you look up, some fading lettering spells out the name 'Doulton'. A smiling caretaker led us to a gallery of photos that tell the story of how John Doulton built a vast business at Lambeth starting from a £100 investment in 1815. The Doultons' fortune was first made in glazed earthenware sewer pipes which saved the city from epdiemics of disease. Doultons then went on to make the fine china that was much admired by Queen Victoria.

A quick trip to London's Number 1 Poultry today. If you can get to the impressive roof garden there are stunning views that more than make up for the irksomely courageous whimsy of the controversial architecture.

Peter Palumbo spent decades acquiring the site site piecemeal from 1958. His scheme to demolish the listed Mappin & Webb building and replace it with what Prince Charles called a 'giant glass stump' - a monumentally impressive bronze coloured steel and glass tower by Mies van der Rohe - was decisively thrown out in 1984.

Palumbo's answer to his critics was to appoint RIBA medal-winner James Stirling to design a vigorously jokey post-modernist block.

Stirling thought he had only a 50-50 chance of success. "I do regard this site as being very special, at this spider's web intersection surrounded by all those heroes like Lutyens and Hawksmoor and Dance. It's the quintessence of London."

Like a stranded submarine decked out in pink stripes, the triangular building seems desperately to be sailing its giant conning tower up the slope towards the Mansion House. The stepped frontage ripples with fiddly bits. Triangles are punched out of the facade and theatrical games are played with circles and squares. The building has a bunker-like rear that currently accommodates a Wetherspoons.

But it uses Portland stone and granite, and it contains echoes of the old buildings on site (if anyone remembers them) so it could hardly upset the purists, could it? Could it ever. Prince Charles demonstrated his familiarity with the latest technology when he said it looked like a 'broken 1930s wireless set'.

Delayed by recession, the design was posthumously completed after Stirling died at the hands of an incompetent anaesthetist. Since then it has regularly won polls for both the best and worst building in London.

Walk into the open rotunda at the centre of the development (with its irritating Dayglo coloured window casements) and take the lift to the Conran-run 'Coq d'Argent' roof garden restaurant and a whole new impression forms.

Wisteria and hawthorn flourish. Fragrant box hedging leads to stunning views of the gherkin and Wren City churches from the glass ship's bridge, either side of the conning tower. Well worth a visit, especially on a Sunday when the people paid to keep rubber-neckers away from the rooftop are less likely to be on duty.

New Zealand company The Conch's 'Vula' was simply one of the most magical evenings I've ever experienced in the theatre. Four women brought the South Seas to sparkling life in the subterranean darkness of the Barbican's Pit Theatre. They performed on a beautifully lit flooded stage - singing, dancing and acting out stories of the sea and everyday life beside it.

Passionate, funny and totally involving tales of church-going, washing clothes, goddesses and fishes, told by four strong, proud and beautiful women. A Fijian audience member wearing a hibiscus flower dress was so moved she couldn't help singing along with the songs and whooping with joy as each new scene unfolded. In the finale a tiny outrigger boat is sung to safe harbour. In any other show it might be a cliché but in Vula it was completely bewitching.

Seven paintings, all of the same subject: a beautiful, almost naked youth, tied to a tree, in the throes of martyrdom. Five are almost identical versions of the same composition, from galleries as far away as Puerto Rico and New Zealand. All are uncompromising in their directness. The painting from Genoa inspired Wilde, Mishima and Pierre & Gilles. Stendahl claimed they so distracted the faithful that they had to be removed from churches.

The St Sebastians of the 'divine Guido' Reni (1575-1642) feature in an exhibition at the Dulwich Picture Gallery until May 11. It offers the public the chance to play an intriguing game of art historical 'spot the difference'. Which are 'real', which are copies? How much is the work of the master, and how much of his studio? Why are they such gay icons?

The Rome painting lacks the impact of its Genoese neighbour. The paintwork is softer, the face and body less defined. A third arrow has pierced the martyr's side and the feathers of another don't now clash with the Roman soldier in the background.

Standing in front of Reni's version from Genoa it is easy to see why it had such impact on Wilde: an athlete of classical build is indifferent to his wounds. Sacred: his boyish, asexual face, framed by his pinioned arms, gazes heavenward. Profane: his loincloth slips provocatively, emphasised by a partly turned hip.

Pierre & Gilles and Jarman also responded to this sultry mix of agony and ecstasy. Yukio Mishima had himself photographed as St Sebastian and in Confessions of a Mask the narrator discovers his sexuality because of a print of the painting.

Of the six versions of the (earlier?) composition, that from New Zealand is the most obviously different. The brushwork is far looser, there is less light - yet in spite of these differences, the current view is that it is by Reni himself. Comparing the others on view, they all seem as one.

The Dulwich's own St Sebastian was long thought to be a copy of the painting in the Prado, Madrid. Now restoration has revealed signs of pentimenti (second thoughts) that have enabled its attribution as Reni's own work.

For one critic Reni was self-consciously re-working notions of light, texture and atmosphere, the repeated composition a means to an end. Perhaps the explanation for so many versions is more prosaic: Reni wanted cash and welcomed requests for repeat business. He certainly went on to make other paintings of this middle-aged Roman soldier, the parton saint of sufferers of the plague, who met his final end only after his wounded body was dragged out of the cloaca maxima. Either way this Dulwich exhibition (which deserved much greater space) is fascinating.

The exhibition is complemented by a catalogue which contains more art historical analysis than is usual. Also on show was 'The age of enlightenment: Beardsley, Dulac and their Contemporaries 1890-1930' - Beardsley's perfumed and obsessional exoticism providing another take on image making.

Comprehensive Survey of images of St Sebastian

Review in the Independent

Given John Prescott MP's unlikely reputation as a lothario, it seems right that he be remembered for giving permision for London's most thrusting new erection - Renzo Piano's 'shard of glass' at London Bridge. Piano describes it as "a vertical town for about 7,000 people" based on "London's heritage of masts and towers".

And since economic ruin is aparently just around the corner what are the chances that financially it doesn't quite rise to the occasion? If it doesn't all go quite according to plan it's apparently the Qatari governement that will get their fingers burnt.

Building a tower taller than everyone else's is not an especially female obsession. Skyscrapers are the phallocratic bullies on the block: they shout down their neighbours, and as Piano says, have a reputation for "arrogance and mysteriousness". He hopes the shard and a matching 'baby shard' nearby will be lively, open spaces, available for the public's pleasure 24 hours a day.

An article in Building Magazine describes the construction of this new 310m high, 88-storey skyscraper, with some excellent animations. The developers promise surgical operations in Guy's Hospital next door will not be disturbed by the £350m work, and that the trains will still run (almost) on time at London Bridge station. Piano's racy design includes a hotel, the inevitable offices and a viewing platform near the top. If you put the Gherkin on top of St Paul's, the shard will still be 21m taller.

Outside Europe they do it bigger. In Dubai they are putting up a tower which will have a spire that will reach 818m, with the 164th floor 194m below. There's even a dam in Tajikstan which at 300m is almost as high as the shard will be.

A pity that all the materials for Prescott's needle will travel by road, even with a major rail terminal next door. If it all goes to plan we should be enjoying the view by June 2011.

See Skyscraper News for the latest on London's tallest buildings.