The Primatial Basilica of the Blessed Virgin Mary Assumed Into Heaven and St Adalbert is an ecclesiastic basilica in Esztergom, Hungary, the mother church of the Archdiocese of Esztergom-Budapest, and the seat of the Catholic Church in Hungary. It is dedicated to the Saint Mary of the Assumption and Saint Adalbert.
It is the biggest building in Hungary and the 18th biggest church in the world. Its inner area is 5,600 m˛. It is 118 m long and 49 m wide. It has a reverberation time of more than 9 seconds. Its dome, forming a semi-sphere, is situated in the middle, and it has 12 windows. It is 71.5 m high inside, with a diameter of 33.5 metres, and is 100 m high from outside, counted from the crypt.
The altarpiece (13.5 × 6.6 metres, depicting the Assumption of the Blessed Virgin Mary, by Michelangelo Grigoletti) is the largest painting in the world painted on a single piece of canvas.
The basilica is also known for Bakócz Chapel (named after Tamás Bakócz), built by Italian masters between 1506–1507 out of red marble of Süttő, its walls adorned with Tuscan Renaissance motifs. It is the most precious remaining example of Renaissance art in Hungary.
The huge crypt, built in Old Egyptian style in 1831, is today the resting place of late archbishops.