At first glance, it appeared to be a stack of wooden pallets being used to transport dozens of bags of charcoal from South America into Europe.
But police and forensics experts had intelligence that told them otherwise.
In fact, the consignment was a haul of 330 million ($540 million) worth of cocaine that had been chemically altered, then dyed to make it look like wood.
Expert "cooks" in Colombia had poured 1.5tonnes of the cocaine mixture into moulds, with the plan to then reverse the process at an industrial-sized drugs-processing plant in the Spanish port of Valencia.
The international drug-smuggling ring behind the plan was broken with arrests across Europe, police revealed.
But the seizure is just the latest in a number of cases that show the increasingly extreme lengths to which smugglers are going.
In October, police seized 300kg of cocaine from a container loaded with pureed bananas that arrived in Valencia from Costa Rica.
Spain's close ties with its former colonies in Latin America have made it the main entry point for cocaine arriving in Europe.
On the latest arrests, Spanish police said: "Two of the Colombians arrested in Spain are expert cooks, deployed to our country in order to reverse the concealment process and thus access the cocaine."
The men allegedly operated a secret laboratory on an industrial estate in Chiva, near Valencia, where the Spanish arrests took place.