Santa María de la Sierra Monastery Ruins
It is the most significant heritage element of Collado Hermoso, having documented records of its existence since the early 12th century. It was occupied by the Benedictine Order at its origin, and in the early 13th century it became the property of the Cistercian Order. Nowadays, part of the church is preserved, with remarkable architectonical elements such as pointed arches and barrel vaults, and as well an awesome rose window at the main façade. The Santa María de la Sierra Monastery Ruins were declared Good of Cultural Interest in 1931 (Bien de Interés Cultural-BIC).
San Nicolás de Bari Church
It is a parish church with a Romanesque style origin, of which are preserved the baptistery access door and the baptismal font. Nowadays it lodges a small museum with several art works of several area churches, with the remarkable Virgen de las Angustias baroque altarpiece, the Romanesque Virgen de la Salud sculpture and the Parish Church processional cross dated in the middle of the 17th century.