Buçaco Sierra (previously spelled as Bussaco, and also once called Alcoba) is an elevation of Portugal mainland, with 549 meters of altitude. It covers the municipalities of Aveiro, Mortágua and Penacova. The forest that still exists today in Buçaco was sent to plant by the order of Carmelitas Descalços in the first quarter of the 17th century. The Carmelitas also built there the Convent of Santa Cruz of Buçaco, used to shelter the monastic order, which existed between 1628 and 1834, the date of dissolution of religious orders in Portugal. Currently in its place is the Hotel Palace Buçaco.
The Buçaco national forest, considered a protected area, has plant species from around the world, some huge, between them the world-famous Cedar of buçaco (Cupressus lusitanica).
It was on this mountain that was fought the battle of Buçaco in 1810, between anglo-luso forces, led by the Duke of Wellington, and the French led by André Massena.