Answer: to Aniston, Alabama - as long as it's an M1 Abrams.
I've just finished watching a National Geographic doco on the life of an M1 Abrams tank. Incredibly, these tanks don't get sent to the scrapyard at the end of their working life; instead, they are completely disassembled, stripped down, repaired, upgraded, and rebuilt.
The tired old Abrams arrives at Aniston to begin the stripping down process. Over 12,000 parts (all barcoded) are removed from the tank, refurbished (including the tracks) and stored in a building with shelves 27 metres high and accessed by an automated robotic retrieval system.
Here at Aniston its massive jet-powered 1500h.p. engine is rebuilt (the plant that originally made the engines stopped doing so in 1992, so no new engines are being produced). An engine rebuild on this sucker takes about 4 weeks.
When the tank is completely disassembled, the bare 20-tonne shell (minus turret) is blasted with stainless steel shot for 90 minutes, removing all paint and rust.
The components are now shipped to Lima, Ohio, for the reassembly process. In a plant with over 500,000 square metres of manufacturing space, each tank is pieced back together over 6 months. Older tanks will require retrofitting of upgraded technology, which means plenty of drilling and chopping.
When the tank is complete, the guns calibrated, and the respray done, the tank is taken to an army base in Fort Bliss, Texas for test firing. It is then shipped overseas for use on the battlefield.
The Abrams has been around for over 25 years now. And the US Army has plans to keep it operational till 2040. Incredible.
And nice to know that 'Reduce, reuse, recycle' is more than just a jingle for the US Army.