Aquincum, the ruins of a two thousand years old forerunner of Budapest, can be found in the northern part of the city. The remains of this civil and military town of the Roman period include two amphitheatres, villas with superb mosaic works, a military bath-house and the stone pillars of an aqueduct.

The Aquincum Museum is a contiguous area of ruins, where the most valuable items include carved stones, wall paintings and an ancient organ.

Old single-storey houses, taverns and fine museums create a unique ambience at Fő tér in Óbuda. Nearby are two museums: the Varga Imre Museum, exhibiting the works of a contemporary sculptor, and the Vasarely Museum housing the complete oeuvre of Victor Vasarely (originally: Győző Vásárhelyi), father of op-art. At the Kiscelli Museum there is a rich collection of works depicting Budapest in addition to 20th-century Hungarian works of fine arts.