Roman Catholic church and Esterházy Mausoleum in Nagyganna, Ganna, Catholic church and mausoleum in Ganna, Hungary

This parish church features a Greek cross layout with a central dome and a marble altar topped by a Virgin Mary statue. The building combines an upper worship space with a lower burial chamber, creating a distinctive two-level arrangement.

Count Miklós Esterházy decided in 1808 to replace Nagyganna's 1770 wooden church. Building began in 1812 to plans by French architect Charles Moreau, but the Tata master builder Joseph Czehmaister was dismissed after a year and Josef Franz Engel, the Esterházy family's building inspector, took over. The church, which cost over 300,000 forints, was consecrated in summer 1818.

The crypt beneath the nave holds 54 Esterházy family members in bronze and marble sarcophagi, grouped by family. A circular marble altar with a crucifix bearing a corpus on each side allowed two priests to celebrate Mass simultaneously, one in white for the living and one in black for the dead. Masses were long said in German, and the church's kermesse falls on 14 September.

The site is open to visitors year-round and is maintained by the Roman Catholic Archdiocese of Veszprém. Regular services take place here, so it is worth checking visit times beforehand to avoid clashing with religious ceremonies.

The flat dome over the nave is painted with coffers and rosettes in imitation of the Roman Pantheon, and the church itself is described as a reduced copy of that building. Its diagonal measures 16 metres, and at the time of construction it was the largest dome in the country.