A total of 950,000 pounds of copper was used to sheath the building and over the course of the next decade it will fade from bright copper to cinammon, then to a rich green that will blend in with the surrounding trees. The interior is centered on a vast, airy lobby. Throughout, you'll find rich native woods and Italian stone, as well as two sliver-shaped gardens planted with ferns and eucalyptus. Selections from the permanent collection of 25,000 works are displayed in galleries on the Concourse and Upper levels. Depending on the art within, some rooms are dim, others bright with natural light; some are small, others monumental. The basement (Lower Level) has a large space for special exhibits and a gift store. In the northeast corner rises a 10-story, gently twisting tower with an observation deck. On the west side of the building you'll find a courtyard café and sculpture park.