The Civil Guard bomb disposal squad in Aragon defused 110 devices left over from Spain's bitter Civil War in the first six months of 2014.
This is twice the number for the same period in 2013.
One of those was found in a pine tree, where it had been suspended for 75 years, Spain's ABC newspaper reported.
Authorities in the region have also been called in to deactivate 28 hand grenades, 21 mortar grenades and four aircraft bombs.
Many of these were found in Teruel which saw heavy fighting during the war.
Spain's Civil War raged from 1936 to 1939 and pitted left-wing republicans against right-wing nationalists, led by General Francisco Franco who went on to become Spain's dictator — a role he held until his death in 1975.
The war continues to create divisions in Spanish society although discussion of the atrocities committed by both sides during the conflict remains taboo.
The United Nations in February said Spain should scrap a 1977 amnesty law that stops victims from prosecuting the alleged perpetrators of such atrocities.