Aretuza was a magical academy for young ladies situated next to Garstang palace on Thanedd Island, that was founded by Klara Larissa de Winter in 839. It consisted of five floors and seventy-six rooms, including rooms for the students. Among the students were girls from the twelve finest families in Redania.
The central hall was built in a "T" shape, and the long side had narrow and extremely tall stained-glass windows which cost a small fortune, reaching almost to the top of the columns that supported the ceiling. The ceiling was so high it could be difficult to make out the frescoes decorating it, mainly nude statues. The many candles throughout the hall were kept alive with magic, so as to be not affected by the slight drought that could be felt. The Gallery of Glory found in the palace displays artefacts from throughout the history of magic.
The annual fees for a student added up to 1,200 Novigradian crowns, with a 200 crown matriculation fee for new students. Adepts studying there were not permitted to leave the island, were forced to abstain from sex, and visitors were only admitted to the lowest level of the academy, Loxia.
In June 1267, Vilgefortz summoned a Grand Mage's Conclave, held on the island, many of the students having been moved away to Loxia beforehand to make room for the visiting mages. On the last night of the month they met in the palace for a banquet.
In 1272, the academy was attacked and destroyed after King Radovid V declared war on magic in Redania. Some novices escaped beforehand with Margarita Laux-Antille to Novigrad in hope they could escape with Triss Merigold's help to Kovir. The students left behind were caught and executed by the Redanian soldiers, only a small handful escaped together with Nina Vivero, another professor of the academy. By the time Geralt and Yennefer rescued Margarita from prison, all of the novices who accompanied her to Novigrad had been burnt at the stake or executed by other means by the witch hunters. Margarita was deliberately kept alive by Radovid to be the final execution until Geralt and Yennefer's intervention.
- Arethusa is a character within Greek mythology.
- In Netflix's The Witcher, Aretuza is treated as being on the mainland while only Tor Lara is on the island nearby.
- The mention of her in dynastic descriptions is unclear about her relation to Aretuza; the way she's described might mean she's either a student or a teacher.