ART: THE FIVE BEST SHOWS IN LONDON

Bridget Riley Serpentine Gallery

The classic Op period: paintings from the 1960s and 1970s, blazing, shifting, and elusively modulating, in black, white, grey, and moving into colour. To 30 Aug

Joseph Beuys: The Secret Block... Royal Academy

... for a Secret Person in Ireland: 456 beautiful and mysterious drawings using blood, fat, pencil and gold leaf offer clues to Beuys' mythology. To 16 Sept

Disasters of War Imperial War Museum

Three ages of European war through the etchings of Jaques Callot, Goya and Otto Dix. Black-and-white flashes of horror, mass-executions, madness and blood everywhere. To 26 Sept

Rembrandt by Himself National Gallery

The self-portraits. The first and most searching autobiography in paint. The great pictorial statements of honesty and mortality, of the human depths. Thirty paintings, plus etchings and drawings. To 5 Sept

Visions of Ruin Sir John Soane's Museum

Small show of follies, fragments and fantasy buildings, detailing the 18th- and 19th-century cult of ruins, in the heart of Soane's house of curiosities. To 28 Aug