Perched on a centrally-located hill beside the Mannerheimintie, the Parliament was constructed in 1926-1931 after the design Oratoribus was drawn up by architects Borg, Sirén and Åberg. This is Finland's only heritage-listed building representative of 1920s Classicism. Its monumental exterior is characterized by 14 Corinthian columns, and is built of red granite. The building is made of Finnish materials, and it represents the unity of architecture, art, workmanship and industrial design. This is apparent in the decor as well as the 900 works of art on display, the most famous of which are the bronze sculptures in the Session Hall designed by Wäinö Aaltonen. Each of the five floors is distinct, connected to the others by a white marble staircase and open lifts. Most important for visitors are the beautiful main lobby, the stately Session Hall and the awe-inspiring Hall of State. Guided tours are arranged on Saturdays and Sundays, and on weekdays in July and August.