The artist Gabriel Orozco invited his friends for a walk this Thursday. The appointment was at one o'clock in the afternoon in the forest of Chapultepec, in Mexico City. The capital's dirty glare forced many to wear dark glasses: horn-rimmed glasses, metallic glasses, round glasses like oranges. "I see that no one brought a hat," observed the artist and started the walk. The invitation was to walk the 400 meters of floating roadway that Orozco designed to unite in a pedestrian way two sections of the forest until now incommunicado.