Agliè's main attraction is its Castello Ducale, one of the Residences of the Royal House of Savoy, listed in the UNESCO World Heritage Sites.

[3] Dating from the 12th century, it was originally a possession of the counts of San Martino.

In the 17th century, it was turned into a rich residence by count Filippo d'Agliè, but was ravaged during the French invasion of 1706.

In 1765 it was acquired by Charles Emmanuel III of Savoy and sold to his son Benedetto of Savoy who had it radically renewed ten years later, under design by Ignazio Birago di Bòrgaro.

It has a monumental façade with two stairs and a fountain; the interior includes 300 rooms, mostly provided with contemporary furniture.