Half of Wales is visible from the blustery summit. “Of all the hills which I saw in Wales,” recalled George Borrow, author of the prolix Victorian classic Wild Wales, “none made a greater impression upon me.” He was not alone. Arenig Fawr, a southern outcrop of Snowdonia, was also the entry point for British art into Post-Impressionism. This at any rate was the claim of a scenic documentary which joined Augustus John and his young protégé James Dickson Innes on their productive two-year sojourn at the foot of the mountain.

That Tracey Emin is one of the defining personalities of our time isn’t in doubt. Even if you never want to hear another second of her guileless wittering, another word about her abortions, traumatic early rape and relentless onanistic neediness, you can't deny that her self-effected transformation from chippy Margate outsider to big-league art-world player represents something extraordinary.

“As a student at Glasgow School of Art I used to visit the amazing anatomy, zoology and ethnographic collections at Glasgow University,” says Christine Borland. “I couldn’t understand why I was so intrigued, except for the question of how something so awful – so dead – could also be so beautiful. I was trying to unpick my responses, to understand how beauty and death could co-exist.”

It is now 37 days since Ai Weiwei was detained at Beijing international airport by the Chinese authorities. His family and friends have heard nothing since. His lawyer, to whom under Chinese law he must have access, was arrested as well, and since his own release he too has heard nothing. Officially, unless charges are brought today, the period in which he can be held without charge expires. And yet, where is Ai Weiwei? The whereabouts of Ai Weiwei the man are unknown. In London, however, Ai Weiwei the artist makes two stellar appearances.

How easy is it to stage a dialogue between two artists when they are, in fact, separated by over a century? And is it really an artistic conversation that takes place or merely an imposition of values by the living over the dead? This pertinent question confronts the viewer in an exhibition of two photographers of war-torn Afghanistan. The first, John Burke, took sepia-toned documentary photographs of the second Anglo-Afghan war, from 1878 to 1880 (the first having taken place in 1839-1842), while the second, Simon Norfolk, takes artfully constructed contemporary photographs that blur the boundaries between art photography and documentary.

In this month of royal weddings, endless bank holidays and (possibly?) equally endless good weather, it can be hard to focus, so perhaps this is the perfect opportunity to catch up with a show that nearly got away. Instead of winsome blockbusters like Tate Modern’s Miró, or the V&A’s The Cult of Beauty, Ivor Abrahams' print show is tart as well as sweet, small but perfectly formed, the ideal restorative after too much sugar, whether in wedding cakes or art galleries.

Freud’s West Hampstead house is tied up in a cat’s cradle of thick rope. The rope is the same colour as the brick, a deep orange but with a sheeny lustre. It makes the house look not quite real, a Brobdingnagian doll’s house transplanted to this unsuspecting corner of leafy west-London suburbia. It’s an uncanny impression heightened by the pristine condition of its squat, many-windowed façade.

Who or what is Jean-Marc Bustamante? This, surely, is the question we are supposed to ask of this artist of the affectless, who has skated in his three-decade-long career across the genres – first photography, then Minimalist sculpture, then a merger of the two, and for the last few years these shockingly vivid “paintings” (I use the scare quotes intentionally) on Plexiglass.

The opening of Turner Contemporary is being heralded as one of the most important cultural events of the year. Described as "a national and international venue in the regions" the gallery, it is hoped, will attract visitors from London and abroad and transform Margate’s flagging fortunes by stimulating new businesses such as commercial galleries, as well as cafés, restaurants and bars.