In 2000 Navarro was invited by the Venice Biennale to participate in an exhibition at the Fondazione Giorgio Cini in conjunction with the seventh International Architecture Exhibition, for which he installed Wall City (Ciudad muralla), begun some five years earlier. Already quite large by the time it was shown in Venice, comprising some 1,000 pieces, Navarro subsequently expanded the installation to include more than 4,000 elements, its current size. Wall City can occupy a space measuring up to 500 square meters—its lateral dimensions vary according to the site—and has towers that soar 4.5 meters tall. Although there are no inhabitants represented in this or Navarro's other Cities, there is nonetheless an implied human presence. Not only does the installation invite the beholder to physically circumnavigate it in real space and, simultaneously, to mentally project himself or herself into the space on an imagined scale, but, according to the artist, "the city [itself] is like a body, and it has flows coursing through its arteries—the horizontal element. In the case of the vertical element, there are walls, towers. . . . The human body uses arteries, veins, fluids, heart, center, shell. When you define a city, you are defining a body."