The small village of Costean consists of a beautiful group of traditional Somontano houses, built with stone and a sandy type of clay, many of which also display fine examples of ironwork.
The parish church of Santiago Apóstol (St. James the Apostol) was built in two stages. In the 16th century the main body of the church was erected with its chapels, and at the end of the 18th century the nave was extended and a wall was erected around its base. This wall was made in several sections set on a brick frame and encompasses a doorway decorated with typically eighteenth-century motifs.
Based in the village, the company Ecostean highlights the age-old Somontano tradition of producing good quality olive oil. The brothers who run the olive oil mill have built on years of family tradition in order to achieve their current standards. The combination of new plantations and century-old trees, equals the production of a range of olive oil of the highest quality, including organic oils.
Its main fiestas are held on the 11th of August in honour of San Lorenzo.