In June and July the average temperature in Buenos Aires is about 15 degrees centigrade. It is too cold to travel furtheron to the south, because winter had just begun in the southern part of the world. We had to change our plans and after long discussions we decided to do a northern loop. We wanted to go in a big loop, passing the Iguazú falls, to Brazil and back down the Atlantic coast via Uruguay to Buenos Aires again. The loop should take us about 2 months and afterwards it is possible to go on south to 'the end of the world'. And furthermore, besides there is also winter north of Buenos Aires, the temperatures should rise again.
And really, after going the first 1000 km up north, to Corrientes, the average temperature was about 10 degrees higher and after 13 hours on the bus we are able to sit outside in the evening again, just with a t-shirt. We skipped our planned trip to a marshy area near Corrientes before taking the bus, because we wanted to visit the original, the Pantanal in Brazil.

After one night in Corrientes we moved on to Posadas, an argentinian city at the border to Paraguay, which is located right beside the Rio Paraná (the second longest river in the world).
Posadas was our base for a day trip to Paraguay and to visit the world heritage declared Jesuit Misions. By taxi we went over the huge bridge between the two countries, passed the border without any problems and arrived in Paraguay. The tourist information at the border was perfectly organized: "If you want to visit the misions, you have to go with the bus xy starting from the bus terminal etc etc and for only one day you have to exchange 100 argentinian pesos, that's enough. Now carrying the amazing amount of 160.000 Guaraí (100 ArgPesos = 25 Euros) we were on our way to the ruines.

Paraguay is a poorer country than Argetina, but not as poor as Peru or Bolivia and the Paraguayos are incredible friendly people. Although we only were there for one day, with our experience so far it was very obvious. Furthermore a lot of germans settled in that part of Paraguay. Companies like 'Seewald Automobile' and towns like 'Hohenau' have still german names.
With the aid of Spain the mision ruins were perfectly restaurated. We visited the first one (Trinidad) together with a guide. In the second one (Jesús) we were perfectly alone, no other tourists to see. It can be different, what we had to encounter the next day, when we visited the mision ruins of San Ingnacio Miní in Argentina. Lots of buses, one artesania shop and restaurant next to the other. We really enjoyed the relaxed atmosphere in Paraguay more.
However the main destination in this part of our trip were the Iguazú falls at the border to Brazil. Unfortunately the last three months there was almost no rain. So in the beginning we were a bit disappointed but in the end it was a really impressive experience. But when visiting the brazilian side of the falls two days later almost 70 percent of the falls were gone. That was really incredible and we were lucky that we had visited the argentinian side two days before!