The study of place names mentioned in the "Gesta" suggests that Anonymus had a detailed knowledge both of the wider region of Óbuda and Csepel Island (in and to the south of present-day Budapest) and of the lands along the upper courses of the river Tisza. For instance, he mentioned a dozen places—settlements, ferries and streams—in the former region, including "a small river that flows through a stone culvert" to Óbuda. He did not write of the southern and eastern parts of Transylvania.