Early museums began as the private collections of wealthy individuals, families or institutions of art and rare or curious natural objects and artifacts. These were often displayed in so-called wonder rooms or cabinets of curiosities. One of the oldest museums known is Ennigaldi-Nanna’s museum, built by Princess Ennigaldi at the end of the Neo-Babylonian Empire. The site dates from c. 530 BCE, and contained artifacts from earlier Mesopotamian civilizations. Notably, a clay drum label—written in three languages—was found at the site, referencing the history and discovery of a museum item.
The Museo del Prado in Madrid(est. 1785).
Public access to these museums was often possible for the “respectable”, especially to private art collections, but at the whim of the owner and his staff. One way that elite men during this time period gained a higher social status in the world of elites was by becoming a collector of these curious objects and displaying them. Many of the items in these collections were new discoveries and these collectors or naturalists, since many of these people held interest in natural sciences, were eager to obtain them. By putting their collections in a museum and on display, they not only got to show their fantastic finds but they also used the museum as a way to sort and “manage the empirical explosion of materials that wider dissemination of ancient texts, increased travel, voyages of discovery, and more systematic forms of communication and exchange had produced.” 
One of these naturalists and collectors was Ulisse Aldrovandi, whose collection policy of gathering as many objects and facts about them was “encyclopedic” in nature, reminiscent of that of Pliny, the Roman philosopher and naturalist. The idea was to consume and collect as much knowledge as possible, to put everything they collected and everything they knew in these displays. In time, however, museum philosophy would change and the encyclopedic nature of information that was so enjoyed by Aldrovandi and his cohorts would be dismissed as well as “the museums that contained this knowledge.” The 18th-century scholars of the Age of Enlightenment saw their ideas of the museum as superior and based their natural history museums on “organization and taxonomy” rather than displaying everything in any order after the style of Aldrovandi.
While some of the oldest public museums in the world opened in Italy during the Renaissance, the majority of these significant museums in the world opened during the 18th century:
- the Capitoline Museums, the oldest public collection of art in the world, began in 1471 when Pope Sixtus IV donated a group of important ancient sculptures to the people of Rome.
- the Vatican Museums, the second oldest museum in the world, traces its origins to the public displayed sculptural collection begun in 1506 by Pope Julius II
- Ambras Castle (Schloss Ambras Innsbruck), Austria, is not the oldest art collection, but it is the earliest collection still to be found in that very building created especially for its museum purpose (1572–1583, Supplement 1589): Ambras Castle is the oldest museum in the world in several respects: the oldest pair of original building and initial collections; the oldest preserved collection in the history of museum according to a systematic concept; it houses – beside the Armouries – the only Renaissance Kunstkammer of its kind to have been preserved at its original location. Verifiably called a ‘museum’ as early as c.1580.
The Lower Castle of Ambras Castle, Innsbruck was one of the earliest buildings of all, explicitly intended for use as a museum, which still exists today in its proper function and shows the original collections.
- the Royal Armouries in the Tower of London is the oldest museum in the United Kingdom. It opened to the public in 1660, though there had been paying privileged visitors to the armouries displays from 1592. Today the museum has three sites including its new headquarters in Leeds.
- Rumphius built a botanical museum in Ambon in 1662, making it the oldest recorded museum in Indonesia. Nothing remains of it except books written by himself, which are now in the library of the National Museum. Its successor was the Batavia Society of Art and Science, established on 24 April 1778. It built a museum and a library, played an important role in research, and collected much material on the natural history and culture of Indonesia.
- the Amerbach Cabinet, originally a private collection, was bought by the university and city of Basel in 1661 and opened to the public in 1671.