This century-old East London gallery began life bringing art to the East End, premiering artists including Pablo Picasso, Frida Kahlo, Jackson Pollock and Mark Rothko, and gaining international acclaim for its exhibitions of modern and contemporary art. The recent £13.5 million refurb has seen it almost double in size, grow a smattering of slick studios and reading rooms, a vast and stunning new interior, and in a stroke of artistic justice gain a rare tapestry of Picasso’s infamous Guernica – which it once showed the original of back in 1939.