The stained glass windows of Santas Creus are the oldest stained glass windows in Catalonia. The monastery is one of the largest Cistercian monastic complexes that can be visited in Catalonia and the only one that retains an extensive series of stained glass windows dating from the early thirteenth century.

The Gothic stained glass windows had already undergone several previous interventions, including a restoration in the sixteenth century and another in the nineteenth century, which used remains of glass and leads from the destruction of the stained glass windows in the sixteenth century by fire.

The stained glass windows of the Cistercian order are characterized by being formed by light-colored glass and drawings that follow geometric patterns without figuration, such as motifs of ribbons that make knots, and some of them were fractured and scattered fragments.

The objective of the intervention was to stop the deterioration processes to which the stained glass windows have been subjected. An isothermal protection glazing system was installed.