Spain is to return to Colombia 691 indigenous artefacts seized in a police operation 11 years ago.
Most of the ceramic items are of huge cultural and archaeological value, and date back to 1400BC.
They had been smuggled out of South America by a man linked to the drug gangs before being recovered in Spain, the embassy in Madrid said.
Following a court order in Spain, the items were handed over to the Colombian authorities.
They were put in the Museum of America in Madrid and will be returned to Colombia in the next few months.
"What we are receiving can be compared to a complete museum," said the Colombian ambassador to Madrid, Fernando Carrillo.
"And they are in good condition too."
They were taken out of the country illegally by a man who specialised in laundering money for the drug cartels, said Mr Carrillo.
Colombia won a long legal battle to avoid the items being returned to their previous owner or remaining in Spain.
The artefacts were made before the arrival of the Spanish colonisers in South America in the 16th Century.
All the main civilisations that lived in the area are represented in the collection.