Royal Netherlands Institute of Southeast Asian and Caribbean Studies

The International Association for Assyriology (IAA) is a non-profit, non-political organization founded in July 2003, and seated in Leiden that "the fields of Cuneiform Studies, ancient Near Eastern History and Archaeology on an international basis and to act as a representative body for these fields in relationship to national, international and private institutions, as well as the general public".According to the Union of International Associations, this organization was founded in "July 2003, London (UK), during International Congress of Assyriology and Near Eastern Archaeology (RAI)" and "registered in accordance with Dutch law."The IAA makes an annual congress, the Rencontre Assyriologique Internationale that assembles scholars from all the world at centres of Near Eastern research. Associations and societies are affiliated like The American Oriental Society, British Institute for the Study of Iraq, Deutsche Orient-Gesellschaft, The Israel Society for Assyriology and Ancient Near Eastern Studies and La Société pour l’étude du Proche-Orient ancien.

Leiden University Libraries is a library founded in 1575 in Leiden, Netherlands. It is regarded as a significant place in the development of European culture: it is a part of a small number of cultural centres that gave direction to the development and spread of knowledge during the Enlightenment. This was due particularly to the simultaneous presence of a unique collection of exceptional sources and scholars. Holdings include approximately 5,200,000 volumes, 1,000,000 e-books, 70,000 e-journals, 2,000 current paper journals, 60,000 Oriental and Western manuscripts, 500,000 letters, 100,000 maps, 100,000 prints, 12,000 drawings and 300,000 photographs. The library manages the largest collections worldwide on Indonesia and the Caribbean. Furthermore, Leiden University Libraries is the only heritage organization in The Netherlands with three registrations of documents in UNESCO's Memory of the World Register. "Est hic magna commoditas bibliothecae ut studiosi possint studere" —Josephus Justus Scaliger"The greatest advantage of the library is that those who want to study, can study."

The Bibliotheca Thysiana was erected in 1655 to house the book collection of the lawyer Johannes Thysius (1621–1653). Upon his early death, he left a legacy of 20,000 guilders for the building of a public library ("tot publycque dienst der studie") with a custodian's dwelling. Designed by the architect Arent van ‘s-Gravensande, the building follows the Dutch Classical style and is regarded as one of the jewels of Dutch 17th-century architecture. Bibliotheca Thysiana is one of the Top 100 Dutch heritage sites. It is distinguished by its balanced proportions and the purity of its Ionic order on top of a high basement. The Bibliotheca Thysiana is the only surviving 17th century example in the Netherlands of a building that was designed as a public library. It is quite extraordinary that a complete private 17th century library has been preserved and thus offers a good impression of the book collection of a young, learned bibliophile from the period of late Humanism. The collection contains about 2,500 books and thousands of pamphlets in all scientific fields. The library also houses one of the 14 still existing bookwheels in the world. The library has a separate special collection of several hundred books from and about Emanuel Swedenborg.

The Hortus botanicus of Leiden is the oldest botanical garden of the Netherlands, and one of the oldest in the world. It is located in the southwestern part of the historical centre of the city, between the Academy building and the old Leiden Observatory building.

Leiden University (abbreviated as LEI; Dutch: Universiteit Leiden) is a public research university in Leiden, Netherlands. Founded in 1575 by William, Prince of Orange as a reward to the city of Leiden for its defense against Spanish attacks during the Eighty Years' War, it is the oldest institution of higher education in the Netherlands, as well as one of the most reputed.Known for its historic foundations and emphasis on the social sciences, the university came into particular prominence during the Dutch Golden Age, when scholars from around Europe were attracted to the Dutch Republic due to its climate of intellectual tolerance and Leiden's international reputation. During this time, Leiden became the home to individuals such as René Descartes, Rembrandt, Christiaan Huygens, Hugo Grotius, Baruch Spinoza and Baron d'Holbach. The university has seven academic faculties and over fifty subject departments while housing more than 40 national and international research institutes. Its historical primary campus consists of buildings scattered across the college town of Leiden, while a second campus located in The Hague houses a liberal arts college and several of its faculties. It is a member of the Coimbra Group, the Europaeum, and a founding member of the League of European Research Universities. Leiden University consistently ranks among the top 100 universities in the world by prominent international ranking tables. It was placed top 50 worldwide in thirteen fields of study in the 2020 QS World University Rankings: classics & ancient history, politics, archaeology, anthropology, history, pharmacology, law, public policy, public administration, religious studies, arts & humanities, linguistics, modern languages and sociology.The university has produced twenty-one Spinoza Prize Laureates and sixteen Nobel Laureates, including Enrico Fermi and Albert Einstein. It is closely associated with the Dutch royal family, with Queen Juliana, Queen Beatrix and King Willem-Alexander being alumni. Ten prime ministers of the Netherlands are also alumni, including incumbent Prime Minister Mark Rutte. Internationally, Leiden University is associated with several leaders, including a President of the United States, two NATO secretaries general, a president of the International Court of Justice and a Prime Minister of the United Kingdom.

The Rijksmuseum van Oudheden (English: National Museum of Antiquities) is the national archaeological museum of the Netherlands, located in Leiden. It grew out of the collection of Leiden University and still closely co-operates with its Faculty of Archaeology. The museum calls itself "the national centre for archaeology" and focuses on ancient Egypt, the ancient Near East, the classical world of Greece, Etruria and Rome and the early (prehistoric, Roman and Medieval) Netherlands.

The Rijksmuseum van Natuurlijke Historie (National Museum of Natural History) was a museum on the Rapenburg in Leiden, the Netherlands. It was founded in 1820 by Royal Decree from a merger of several existing collections. This happened on the initiative of Coenraad Jacob Temminck, who saw the museum primarily as a research institute for the University of Leiden. The total collection was already quite large at the time, and continued to grow from foreign expeditions and by obtaining private collections from inheritances. The location is currently used by the Rijksmuseum van Oudheden.

Leiden Observatory (Dutch: Sterrewacht Leiden) is an astronomical institute of Leiden University, in the Netherlands. Established in 1633 to house the quadrant of Rudolph Snellius, it is the oldest operating university observatory in the world, with the only older still existing observatory being the Vatican Observatory.The observatory was initially located on the university building in the centre of Leiden before a new observatory building and dome were constructed in the university's botanical garden in 1860. It remained there until 1974 when the department moved to the science campus north-west of the city. Notable astronomers that have worked or directed the observatory include Willem de Sitter, Ejnar Hertzsprung and Jan Oort.

Oudt Leyden is a restaurant in Leiden in the Netherlands. It is a fine dining restaurant turned pancake-restaurant, that was awarded one Michelin star in 1957 and retained that rating from 1957 to 1979. It was again awarded a Michelin star in 1985 and retained that rating until 1989.Oudt Leyden is one of the founders of Alliance Gastronomique Neerlandaise. In 1967, owner was S.M. Borgerding.

The Pieterskerk is a late-Gothic Dutch Protestant church in Leiden dedicated to Saint Peter. It is known today as the church of the Pilgrim Fathers, where the pastor John Robinson was buried. It is also the burial place of the scientist Willebrord Snellius.

The Gemeenlandshuis van Rijnland on the Breestraat in Leiden is the oldest Gemeenlandshuis of the Netherlands that kept its function until the current century. Currently, it is still in use by the Hoogheemraadschap van Rijnland, but only for meetings and special occasions. Their day-to-day seat of water management is housed today on the Archimedesweg in Leiden.

Museum De Lakenhal is the city museum of fine art and history in Leiden, Netherlands. One highlight is its collection of fijnschilder paintings from the Dutch Golden Age. Just like the city, the museum combines a classical appearance with a contemporary character. The broad collection ranges from early works by Rembrandt van Rijn and Lucas van Leyden's Last Judgement to modern classics of De Stijl and artworks created by contemporary artists such as Claudy Jongstra, Atelier van Lieshout and many others.