The National Library is home to several million pounds in an ever-growing collection, but also an impressive archive of thousands of documents and more than 20,000 newspapers. It has one of Spain's most important collections of drawings and engravings, and 800 000 posters and over 2 million photographs.
The library is currently closed for the renovation of the museum, but the catalogs can be viewed online.
The collection is the home of 134,000 maps and cartographic operations specialist, and a huge postcard collection. The Music section contains music-related documents, such as printed scores and sound and video recordings. Sculptures of famous writers such as Cervantes takes you to the library halls, and although all exhibits labeled in Spanish, catalogs can be purchased in other languages.
The Museum of Archaeology in the other part of the building by the Royal Decree of Isabel II, founded in 1867 to jointly archaeological collections from different institutions. It was transferred to the current building in 1895.
Major exhibits include the Dama de Elche (Lady of Elx), a fourth-fifth century BC bust of a woman who may have held relics or funereal ashes. The Dama de Baza, discovered in a necropolis in the province of Granada, is from the 4th Century BC. The magnificent Tesoro de Guarrazar collection represents the religious treasures of the Visigoth kings of the Iberian Peninsula and was discovered near Toledo.
The Visigoths, of German origin, were Christians, and ruled the peninsula from Iberican end of the Roman period until the arrival of the Moors in the 8th Century. The museum also contains the similar Visigoth treasure Torredonjimeno found in the province of Jaen in Andalucia. These displays are complemented by other items of Egyptian mummies and sarcophagi, as well as Roman mosaics and Greek pottery.
Just below the gardens of the museum you can see reproductions of some of the oldest cave paintings in Europe, the Cuevas de Altamira (Altamira Caves), in Cantabria in northern Spain. The original paintings from the period around 12,000 BC, showing a herd of bison.
source:http://www.gomadrid.com/museums/biblioteca-museo-arqueologico.html