No, you cannot walk directly between the two sides inside the national parks. The falls are separated by the Iguazú River, and there is no pedestrian bridge or trail connecting them. To cross, you must go through border control at the Tancredo Neves International Bridge, which connects Puerto Iguazú (Argentina) with Foz do Iguaçu (Brazil). We have many tours available to organize two visits in different days, or you can combine the visit to both parks in one single day, by booking a private service.
If you´re on your own, you can take a taxi, private transfer, or a public bus to cross the border but we reccommend to organize a tour with guide. Ensure you carry your passport and check visa requirements for Brazil or Argentina based on your nationality. Important, the border crossing times vary but typically take 30–60 minutes, depending on traffic and immigration procedures.
If you only have one day, and a reduced time, most travelers recommend visiting the Argentine side, as it has more trails and closer views of the falls. But check with us, as it´s possible to visit both parks in one single day.