The Loire Valley, known as "The Garden of the France" was the favorite residence of the Kings of France during the Renaissance. These are buildings for the most part built or heavily remodeled in the French Renaissance, at a time when the royal power was located on the banks of the river, its tributaries or near them (fifteenth and sixteenth centuries). Most castles nevertheless have their origins in the Middle Ages from which they retain important architectural features. The concentration of remarkable monuments in this region has justified the classification of the Loire Valley as a World Heritage Site by UNESCO.