city and departmental capital of Amambay, Paraguay
Pedro Juan Caballero is a border town of 116,000 (2016) in Northern Paraneña region of Paraguay. It is across the road from Ponta Porã in Mato Grosso do Sul, Brazil.
The two towns are divided by an avenue, with free transit between the two sides of the border. You must present yourself for immigration formalities, and the Paraguayan and Brazilian sides are in different buildings — both are walking distance from PJC center. There are reports the Brazilian side is only open from 09:00-16:00. If you have an early bus, considering doing the border formalities the day before.
All these buses go by Yby Yaú, which can be a convenient transfer point.
There're no local buses in Pedro Juan Caballero, only taxis. So it's about 2 km walk along PY-05 from the corner PY-05/Av. Fernando de la Mora to the Paraguay Migration Office. Most buses stop there. Don't go to the bus terminal, that's 3 km further away.
Ponta Porã has a few commuter bus lines by Medianeira Ponta Porã, check the time tables.
The town is a shopping destination for Brazilians due to its offer of cheaper imported goods. If you need to resupply on camera or camp gear, what can be found in Paraguay is much cheaper than in Brazil.
The border is open, you can sleep in any side of the border regardless of immigration formalities. But do get your stamps before onward travel.