▁anten na ▁was ▁installed ▁at ▁the ▁top ▁of ▁the ▁tower ▁to ▁broadcast ▁radio ▁program mes ▁of ▁the ▁channel ▁" Al pes - G reno ble ". ▁ ▁Now ad ays , ▁Per ret ▁Tower ▁is ▁the ▁only ▁rem nant ▁of ▁the ▁exhibition . ▁This ▁tower ▁allowed ▁Per ret ▁to ▁prove ▁the ▁huge ▁ability ▁of ▁rein for ced ▁concrete ▁and ▁make ▁him ▁famous ▁as ▁a ▁great ▁architect . ▁ ▁Today ▁In ▁ 1 9 6 0 , ▁the ▁tower ▁was ▁closed ▁to ▁the ▁public ▁due ▁to ▁its ▁de grad ation . ▁In ▁ 1 9 9 8 , ▁it ▁was ▁officially ▁declared ▁to ▁be ▁a ▁national ▁her itage ▁site . ▁Currently , ▁the ▁top ▁of ▁the ▁tower ▁is ▁ill umin ated ▁during ▁the ▁winter ▁and ▁is ▁used ▁as ▁a ▁support ▁for ▁the ▁fire works ▁of ▁the ▁ 1 4 th ▁of ▁July . ▁ ▁No ▁serious ▁maintenance ▁was ▁made ▁after ▁the ▁exhibition , ▁and ▁the ▁tower ▁de grad ation ▁might ▁become ▁irre vers ible : ▁iron ▁frameworks ▁are ▁uns he athed ▁or ▁broken ▁and ▁ox id ization ▁of ▁the ▁iron ▁framework ▁leads ▁the ▁rein for ced ▁concrete ▁to ▁cr umble . ▁In ▁ 1 9 5 1 , ▁a ▁fac ade ▁sc re ed ▁was ▁made ▁( not ▁efficient ▁for ▁life ▁span ). ▁In ▁ 2 0 0 5 , ▁a ▁study ▁by ▁A lain ▁Till ier , ▁chief ▁architect ▁of ▁the ▁national ▁her itage ▁sites , ▁estimated ▁the ▁rest oration ▁cost ▁at ▁ 4 . 5 ▁million ▁eu ros . ▁No ▁work ▁was