Washington's so-called "rendition program," under which suspected Islamist militants from conflicts in Afghanistan and Iraq were spirited to jails outside U.S. jurisdiction, remains shrouded in secrecy.
But the European Court of Human Rights has confirmed the 10-room building, in a pine forest of the village of Antaviliai outside Vilnius, was used by the CIA to hold terrorist suspects from 2005-2006.
The Lithuanian government's real estate fund, which handles assets no longer needed by the state, is preparing to offer the barn to the market at a yet-to-be-decided price.
The fund took over the site from Lithuania's intelligence service which used it as a training facility from 2007-2018.
Lithuania's defence minister Arvydas Anusauskas, who led a Lithuanian parliamentary investigation into the site in 2010, said it was somewhere "you could do whatever you wanted".
A local resident who gave his name as Alfredas said, "I am a construction worker. They dug so much ground. So they must have three or four floors under the ground. The whole field was covered in earth. So, what was going on there? And they say that nothing happened."