Border crossing in Iguassu Falls are open

Borders between Brazil and Argentina
Foreign people will be able to cross only from November first. 
To visit both sides of the falls, one must cross the borders between Argentina and Brazil.

Iguazu borders are open, to cross it is mandatory to show the covid-19 vaccine proof and also a 72 hours PCR negative OR make a swab test at the border. 

Borders between Brazil and Paraguay
To enter Paraguay one needs to stamp the passport at the border and show the covid-19 PCR test. For people that visit Ciudad del Este city, they don't require anything. People usually go to Paraguay for shopping because of the duty-free markets there. There is a small waterfall called Monday falls near Puerto Franco town. One can also visit the Itaipu Dam from the Paraguayan side. In the city, there is also a handicraft market with beautiful wood carving souvenirs.

Both national parks around the falls are open.