Lonely Planet review
Ó means 'ancient' in Hungarian; as its name suggests, Óbuda is the oldest part of Buda. The Romans established Aquincum, a key military garrison and civilian town north of here at the end of the 1st century AD, and it became the seat of the Roman province of Pannonia Inferior in AD 106. When the Magyars arrived, they named it Buda, which became Óbuda when the Royal Palace was built on Castle Hill and turned into the real centre.
Most visitors on their way to Szentendre on the Danube Bend are put off by what they see of Óbuda from the highway or the HÉV commuter train. Prefabricated housing blocks seem to go on forever, and the Árpád Bridge flyover splits the heart of the district (Flórián tér) in two. But behind all this are some of the most important Roman ruins in Hungary, noteworthy museums and small, quiet neighbourhoods that still recall fin-de-siècle Óbuda.