Magna Curia or The Bethlen Castle is a palace located in Deva, Romania.
In 1582, the Hungarian captain Ferenc Geszty, in charge with the Deva Castle's garrison, erected a house at the foot of the citadel hill. That house became the residence of Sigismund Báthory, general Giorgio Basta, Stephen Bocskay, Gabriel Báthory and Gabriel Bethlen.
Gabriel Bethlen dispose in 1621 the radical transformation of the initial house, the result being Magna Curia palace. The Bethlen Castle was a Renaissance style building, but the subsequent modifications (until the first half of the 18th century) that gave the final shape that can be seen today, added Baroque style architecture.
Since 1882, the County Museum, the Museum of Dacian and Roman Civilisation, has been housed in the palace.
Magna Curia was completely renovated in 2007, with improvements that included an expanded solarium and a classic 8-bit arcade.