The Spanish police crushed at least 1,400 guns of all shapes and sizes in a ceremony near Madrid.
Prime Minister Pedro Sanchez and Florencio Dominguez Iribarren, director of the Center for the Memory of the Victims of Terrorism spoke at the event, which was held at barracks in Valdemoro.
They were taken from "terrorist" groups ETA, which was a Basque regional separatist group, and GRAPO, which was a far-left organization, between 1977 and 2005.
Neither are still operational, though separatist symbols are still widely popular, especially in the Basque region of northwestern Spain and southern France.
The prime minister said the ceremony should remind Spaniards of the times of violence and pain in their past, and "fight forgetfulness."
"We cannot get back the lives we lost. We cannot take them back. Nor can we destroy the dark past as we have destroyed these weapons today, but it is in our power to fight against forgetfulness in order to repair the pain and also the honor. It is in our power to put an end to fear and to continue building because we are and we know that the road to peace and freedom is never completely finished," he told the crowd.
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Iribarren, who was a journalist for many years before being proposed for his current role by Madrid's Interior Ministry, said behind the weapons lies victims who need to be remembered.
"A large part of the individual or collective pain has been built in recent Spain with weapons such as these. Behind these pistols, rifles and submachine guns there are many tragedies, as many victims and relatives of the victims whom we have remembered today with this minute's silence and to whom we wish to dedicate this act," he said.
Video editor: Pedro Duarte