The observatory and the Lyceum building complex was commissioned by Count Bishop Károly Eszterházy of Eger in 1764 as a part of planned university. He speared no expense to obtain the best – and possibly the biggest – a equipment of the age, mostly from England. According to his conception the observatory tower – as called then in Latin “specula” – would serve for both educational and scientific research purposes.
The bishop contracted Jakab Fellner – the distinguished Hungarian late baroque architect – in 1764 to build a four faculty (law, theology, medical and science) universitas. To the interior of the tower – as instructed by Eszterházy – Fellner interviewed astronomers Miksa Hell and János Madarassy. The observatory tower was ready to the top level in 1776 and its instrumentation had been started. The building was finished by 1785. In the meantime the regulation of education was issued (Ratio Educationis 1777) and it turned the planned university to a seminary and later to a secondary school. Neither financial nor educational potential remained for a grandiose observatory. When in the beginning of 19th century again a talented mathematician, Pál Tittel (1784-1831) served in the observatory, the equipment was out of date, and no substantive astronomical work could be carried out. The tower later has become a museum thanks to Endre Zétényi.
In 1868 the Society of Hungarian Physician and Natural-searchers usual annual assembly were held in the lyceum of Eger, Hungary. As it was a custom a commemorative medal was issued for the occasion. The medalist depicted the facade of the lyceum and the astronomical tower. Text above: "EGER A MAGYAR ORVOSOKNAK ÉS TERMÉSZET/ VIZSGÁLÓKNAK 1868. (From Eger to the Society of Hungarian Physician and Natural-searchers 1868). Below the facade and the specula "EGRI ÉRSEKI/ LYCEUM", (archiepiscopal lyceum, Eger)
On the reverse two coats of arms is visible, one for the town Eger, another for county Heves. Above the coats of arms a winged cherub's head is depicted, below SEIDAN. The whole is wreathed by grape and wheat. The medal was a work of Wenzel Seidan (1817-1870) a Prague born medalist in Vienna.
The astronomical tower is a museum today, and several astronomical “relics” are exhibited, among them the Hell-Bell, that was used to signal the noon to the people of Eger until 1890. The most interesting attraction of the museum is the meridian, that was settled by Miksa Hell, and according to his wish was built from Carrara marble. The meridian is constructed from three paths, the center path is consisted of 12 Carrara marble plates. The other two paths contains partly marble, partly crystallized limestone from Tárkány. The meridian work as a enormous camera obscura, a small hole on the ceiling casts the light of Sun to the room, and the image of Sun passes through the center of the meridian line marking the local noon of Eger.
