The island was created from debris carried by the Danube river. The coast of Óbuda lies between 1651st and 1654th km river marker. It has an area of 108 hectares, a length of 2750 m, a maximum width of 500–500 m directly in line with the 1653rd km river marker. Obuda Island is separated by a 70 to 80 meter wide branch of the Danube. Not far from the northern end of the Újpest railway bridge, the southern end of the Árpád Bridge connects Buda and Pest.
Originally it was a reef island, made up of two close standing parts
