The Science Museum has a building area of over 42,000 square metres, of which 26,000 square metres are for exhibitions. The building is on three floors. The ground floor includes the so-called Calle Menor, which houses the main services open to the public (ticket offices, restaurants, shops,...), and access to the Santiago Grisolía Auditorium and the Salón Arquerías where all kinds of congresses and events are held. The Calle Menor is open free to the public and is the venue for a number of exhibitions throughout the year.