José Antonio Tallón Iglesias (SOMOS.arquitectos) publication in CLOG, in a special number about the World Trade Center, including an abstract from the PhD dissertation about Gordon Matta-Clark and Twin Towers with the title "The Space In Between".

"At the time of the World Trade Center ribbon cutting ceremony, on 04 April 1973, a group formed by the architect Gordon Matta-Clark was born in Manhattan. They have been meeting together giving shape to a new spatial attitude: Anarchitecture. The aim of the group was to explore the city looking for new forms of experienced space more than finished built space.

In March 1974 the “Anarchitecture Show” opened at 112 Greene Street. It was originally conceived as a show of documentation in which each participating artist was to anonymously hang photographs about different experienced spaces with architecture as a common denominator. But a relevant photograph was included in the repertory: a deliberate fragmented view of the World Trade Center focusing all the gazes on the void between the twin towers. The title was also consistent: “The space in-between”, highlighting that the emptiness amidst the two monoliths was even more important than the built space.

Matta-Clark was simultaneously attracted by the in-between space and repelled by the two solid built masses. He imagined the twin towers like long scrolls of endless city inside two obelisks that towers at any size, exemplifying a distorted form of monumentality: the un-monument. Two cyclopean accumulations of gray substance completely sealed which avoid any dialogue with the environment and invites you to move away. Twinning is their only originality, representing the culmination of a period in which the box with no attributes has emerged as the most effective model.

The success of the curtain wall ensures the un-monument that rises solipsistic, holding but not containing. Matta-Clark used it as a gray backdrop in many of his photographs and performances for Anarchitecture.

But Matta-Clark preferred to explore a new category of monumentality that appears in the in-between space: a non-monument to emptiness that transforms the zero degree architecture of the World Trade Center in a “monument to experienced void”. Matta-Clark became fascinated with the gap contained between the towers and, in 21 January 1975, he wrote a letter to Robert Lendenfrost suggesting a collective anarchitectural proposal to use different spaces of the World Trade Center as an opportunity to contribute some positive insights within the new scale an complexity of the Center. The proposal was finally rejected, but we can be sure that Matta-Clark would have chosen the in-between space to imagine how to occupy and inhabit that new monument to the void. He probably would have conceived a performance based on his projects such as “Tree Dance” or “SkyHooks”, using wires and playing with the empty space as a perfect scenography for performing his work.

But five months earlier, on 07 august 1974, the funambulist Philippe Petit inhabited the 200 feet of void that separates the twin towers using only a wire. Petit performed for 45 minutes, during which he walked, danced on the wire and saluted watchers: the in-between space was experienced for a moment! Through this performance Petit made his dreams come true, but probably also those of Matta-Clark… "