Do try Brick Lane in London, early on Sunday morning. It's a great street market, plus has some of London's best architecture - early Georgian houses, but in quite a gritty, urban setting. You can take photos at the Beigel Bake (the last one, on Brick Lane itself, you can see them making them in the back). Actually Don McCullin took photos there. It's where every wave of immigrants to London settled - Huguenots, Jews, Bengalis, and is a fascinating mix of culture, with a beautiful church which was built circa 1717 to intimidate the unruly inhabitants, and impress them with the power of the monarchy & the church Of England. I think Jack The Ripper despatched one of his victims in the churchyrad, and several of them drank in the pub opposite called, I think, the Seven Bells. . There's a great flower market, nearby, too, at Columbia Road, and a good covered market in Spitalfields. Look out for a couple of middle-aged men in tweeds, slightly old-fashioned - they're gilbert & George, who were in inspiration to the 'Britart' movement, and inspired many artists to move to the area. If you see someone with a four year old boy, and a CL, that's me, I go there every Sunday when I'm at home.
In Glasgow, look out for buildings by Alexander 'Greek' Thompson. He's Glasgow's unsung architect, late Georgian, some of his buildings are quite neglected, and are starting to look like ancient greek ruins. One of them is on, I think, Caledonia road in the Gorbals, which is also an 'interesting' area! Enjoy your trip!