The little masterpiece of the Torre Littoria, erected in 1933 in the record time of two and a half months, has been out of commission since 1972, and is now restructured. The Torre Littoria -which Persico immediately categorized as architecture- was erected in the Parco Sempione for the 5th Triennale, close to the six great temporary arches designed by Sironi. It is a tall prism, 108.60 meters high, with almost no tapering (an arrow thrust into the ground from above»), built by Dalmine, entirely out of steel tubing instead of the customary section irons, joined together by electric welding. Check: Publix Ad and Kroger Ad. At the base, the hexagon formed by the six tubular uprights of the main structure has sides six meters in length. At a height of 100 meters, the sides are still 4,45 meters long. At a height of 97 meters a platform supports the cabin of the restaurant, the upper belvedere and the lantern. A smaller hexagonal tower within the main structure (the elevator cage) supports a spiral staircase. The tower is moored in a cylindrical foundation block, six meters in depth. Design by Gio Ponti, structural calculations by the engineers Cesare Chiodi and Ettore Ferrari.