Puerto Iguazú itself is small and walkable. Taxis and remises are plentiful and cheap by European standards; most journeys within town take ten minutes.
To the Argentine park: Local buses run between the town centre and the national park entrance (approximately 30 minutes). The park has its own internal transport system — a small train that runs to the Garganta del Diablo trailhead, and shuttle buses connecting the visitor centre to the circuit trailheads.
To the Brazilian side: Taxis take 30 to 45 minutes from Puerto Iguazú, crossing the Argentine-Brazilian border at the Tancredo Neves Bridge. Organised day tours from town include transport and can also arrange the park entry tickets.
To Paraguay: Ciudad del Este in Paraguay is reached via Foz do Iguaçu and the Friendship Bridge across the Paraná. The crossing involves two border controls (Brazilian exit and Paraguayan entry) and is most manageable by taxi or organised tour rather than attempting it independently on foot.