They resist while time transforms life around them. Thus, restoring them becomes a challenge when it comes to integrating current techniques and materials while preserving their essence, which has made them part of the landscape and of history.

At the end of the 19th century, large, forged metal skeletons were raised, such as those of the Palacio de Cristal of Retiro, or the Calatorao marble plinths in the Central Market in Zaragoza. Even earlier, in the 16th century, the Plateresque and Mudejar brushstrokes were made in what is now the Picasso Museum in Málaga. Centuries later, restorations incorporate modern features such as resistant glass, solar control glass enclosures and sustainable air conditioning systems.