Authorities have displayed 2,000-year-old silver coins that were looted a decade ago from an archeological site in Transylvania and smuggled to the United States.

The 49 coins were publicly exhibited at the National History Museum Monday for the first time since they were stolen in 2003 from Sarmizegetusa Regia, a UNESCO-recognized archaeological site recognized, with the aim of selling them on the international black market.

Police said the coins were identified at a Chicago auction house in 2011. It took two years for the coins to be returned to Romania, with the help of the FBI, Romanian anti-crime prosecutors and government officials.

In recent years, more than a dozen people have been sentenced or are being prosecuted for looting and selling items abroad on the black market. The coins were minted between 29 and 44 BC; no value was given for them.