Set beneath the foliage of Green Park the tunnel between the Victoria, Piccadilly and Jubilee lines, like the burrow of the waist-coated rabbit, propels me into realms of unreality. I feel utterly transported as the psychedelic patterns on the walls play with your senses, distorting perspectives as the world around me becomes curiouser and curiouser. The tiny blue and grey mosaic tiles, no bigger than a piece of chocolate, scatter themselves across the curved walls. As I walk through them I am elevated, as if in Willy Wonka’s television experiment piece by piece, little by little into another dimension. Their straight edges, so defined, so measured in shape, are scattered chaotically over an arch of indefinite wall and ceiling. They spin into one another with such uncertainty I half expect the floor to rotate beneath me into an unrelenting abyss of squares and circles, sending the commuters with their briefcases tumbling like lottery balls into oblivion. The whirring of the ventilation system, the bursts of hot wind from moving trains, blowing my hair and clothes around my body, suck me further down this tube of delusion and enchantment. Only as the whirring gives way to the jazzy music of a busker do I find myself stood on the dull, even platform waiting, like everyone else, to go home again.