The famous SW3 sanctuary has opened its gates to contemporary art this summer. The oldest botanical gardens in Europe have invited a group of artists to make works for installation within that convey the essence both of the almost secret location and the health-giving range of medicinal plants. Visitors must search for the pieces over some three and a half acres. But many will not be over-concerned, taking this as a great opportunity anyway to view the gardens themselves. The exhibition, entitled modestly Art in the Garden, remains open through 15 September.