The Weekend's Television: Kevin McCloud's Grand Tour, Sun, Channel 4<br/>Trinity, Sun, ITV2<br/>Peep Show, Fri, Channel 4

There's a bit of scaffolding around in Kevin McCloud's new Channel 4 programme, but very few builders and none of those sequences when he discreetly makes it clear that he thinks an architectural faux pas is expensively and tardily being committed.

This is because virtually every building he visits was completed well over 300 years ago, and have been regarded as architectural treasures ever since they were topped out. One imagines Palladio must have had bad days with errant builders and Inigo Jones sometimes changed his mind mid-build, but all that is long in the past now. In Kevin McCloud's Grand Tour, Channel 4's resident building buff is retracing the steps of the young aristocrats who went on "history's equivalent of the gap year" and he is in rhapsodic mood.

He started in Covent Garden, the point being that here in the heart of London was a little bit of Italy, a souvenir brought back home by an architect in love with continental style and the classical revival buildings of France and Italy. And then it was off to Paris on the Eurostar, first to have himself kitted up as a complete ninny at a high-end couturier (much as the original grand tourists would have done) and then to wander dreamily round the Place des Vosges, which minus the trees and the Parisian gravel and the lapdogs attached to elegant dames, had been vaguely replicated by Jones back in Covent Garden Piazza. That's the deal here – it's part travel show, part history programme and part architectural gazetteer. In Genoa, McCloud interviewed an unusually bookish-looking prostitute (the Grand Tour was a sexual adventure as much as a cultural one), in Parma he called in on a cheese-maker and in Venice he guided us through the piling techniques of the palazzo builders with the help of cocktail sticks and a bowl of chocolate blancmange.

He also sketches a lot, which is a very Grand Tour kind of thing to do, though he seems a bit cagey about showing the results to the camera, even though you can see from the odd glimpse that they're perfectly creditable. I think he's also probably been a lot more restrained than his 17th and 18th-century predecessors, steering well clear of bordellos and opting to spend the time instead with Capuchin brothers, gasping at the purity of structural proportions. It's a perfectly pleasant way to spend a Sunday evening, anyway, and a good deal cheaper than doing the trip yourself.

I can't imagine that there will be a big demographic overlap with the potential audience for Trinity, ITV2's weird gothic thriller, set in a fictional Oxbridge-style college. The first time I looked at this the online screening system stuttered wildly, so that the soundtrack ran fluently beneath a series of still images of the characters gaping wildly. It was like a strange high-tech version of Deidre's Photo Casebook from The Sun, and it seemed appropriate really because all the dialogue here would be far more at home in a speech bubble. The story begins with the death of a vicar in a mist-swathed churchyard and then shifts to new term at Trinity, a traditional establishment just about to take its first intake of swotty oiks. The college's usual students – dandyish young toffs who are majoring in advanced hooliganism and applied debauchery – don't think much to this. There is boy tottie and girl tottie, a lot of sophomorically naughty sex, and a couple of comedy dopers who are about as funny as accidentally stubbing a joint out on your own kneecap. What there isn't is a shred of psychological continuity, so that at one moment a mousey Christian student is expressing shock at what one takes is her first sight of a naked man and at the next she's helping him to peel off her knickers. It wants to be so bad it's good, but sadly it's not quite bad enough to make it.

Peep Show returned on Friday - with Jeremy reluctantly taking up a job at JLB International, only to be made redundant – along with everyone else in the business – before it's even time for mid-morning coffee. This was a great disappointment for Mark, who had been hoping to exploit his newly acquired managerial power ("Maybe I could make him wear a little coloured hat like a chimpanzee," he'd mused, as they set off for work). He was also dismayed that Jeremy seemed to feel that a one-and-a-half-hour service record qualified him to be as stunned by dismissal as someone who'd been working his way through the cubicle farm for five long years. "You're freeloading on my trauma! You're a grief thief!" he complained, when Jeremy murmured something collegiate about the shock. It all ended badly after Mark had rallied his employees in rebellion against head office, for the sole purpose of getting Dobby into bed. It all ended badly, that is, in a very good way.