The stone terraces (terraced alpinum) are located on the western side of the castle in the vicinity of the so-called castle bastion. The individual alpine terraces are supported by stone walls built of local Algonquian slate. The individual terraces are partially shaded by trees and are planted with shrubs and groundcover, mostly shade-loving perennials, shrubs and bulbs. It was here that Count Silva-Tarouca is said to have made his first attempt at establishing an alpine garden and planting alpines. The terraces began to decay over time, and the terraced alpinum was restored to its original form in 2016.