The Lyceum (Ancient Greek: Λύκειον, Lykeion) or Lycaeum was a temple dedicated to Apollo Lyceus ("Apollo the wolf-god").
It was best known for the Peripatetic school of philosophy founded there by Aristotle in 334 / 335 BCE. Aristotle fled Athens in 323 BCE, but the school continued to function under a series of leaders until the Roman general Sulla destroyed it during his assault on Athens in 86 BCE.
The remains of the Lyceum were discovered in modern Athens in 1996 in a park behind the Hellenic Parliament.
The Lyceum had been used for philosophical debate long before Aristotle. Philosophers such as Prodicus of Ceos, Protagoras, and numerous rhapsodes had spoken there. The most famous philosophers to teach there were Isocrates, Plato (of The Academy), and the best-known Athenian teacher, Socrates. In addition to military training and educational pursuits, the Lyceum also housed Athenian Assembly meetings before the Pnyx became the official meeting place in the 5th century BCE. Cult practices of various groups were also held at the Lyceum.
In 335 BCE, Athens fell under Macedonian rule and Aristotle, aged 50, returned from Asia. Upon his return, Aristotle began teaching regularly in the morning in the Lyceum and founded an official school called "The Lyceum". After morning lessons, Aristotle would frequently lecture on the grounds for the public, and manuscripts of his compiled lectures were eventually circulated. The group of scholars who followed the Aristotelian doctrine came to be known as the Peripatetics due to Aristotle’s tendency to walk as he taught.
Aristotle’s main focus as a teacher was cooperative research, an idea which he founded through his natural history work and systematic collection of philosophical works to contribute to his library. His students were assigned historical or scientific research projects as part of their studies. The school was also student run. The students elected a new student administrator to work with the school leadership every ten days, allowing all the students to become involved in turn. Before returning to Athens, Aristotle had been the tutor of Alexander of Macedonia, who became the great conqueror Alexander the Great.