After 2 nights at the Belmond, it was a leisurely breakfast and a 9:30am pick up for my tour of the Argentine side and drop-off at the Argentine side airport.
I asked about changing money - the park fee is 240 pesos cash only. We stopped at quite a big tourist trap on the highway, where I changed my money, the driver bought me a coffee (really nice) and I was able to gaze upon all the goodies from sale, from monster amethyst geodes, to t shirts, to pre-mixed caipirinha! I bought a bottle of the latter and I'm sure the driver got his commission
The drive to the Argentine border was about 35 mins; we cleared Brazil departure immigration with me sitting in the car while the driver went inside the building with my passport; onwards to the Argentine immigration area a km or so past the river crossing (???). There, I produced my receipt for having paid the 'reciprocity fee', my passport was taken while I was still in the car, and I entered Argentina, with the border agent never having looked me in the face (Brazil agent neither, for that matter).
The park was another 20 mins or so drive. The Argentine park / viewing area is much more structured than the Brazil one. There is a large entry complex, with a number of paths. There is an ATM at the park entry place, but its often out of order (it was working for me, but wanted to charge some fee on my Citi Plus debit card, so I declined)
The park entry complex is at the bottom right in the map below. There is a 200m walk to a little train that takes you from there ('Central Station') to the Devils Throat drop-off point (abt 20 mins - top of the map), via one other stop where the 'middle circuit' leaves from (orange trail). There is also a 'lower circuit' (white trail), that takes you to the river, and boat rides, and that leaves from the same point. All the paths and facilities are in good order.
This is the train - it leaves about every 30 mins. It seemed a bit chaotic in boarding etc (in the South American way) and also there was a bit of backwards shunting back and forth. Fortunately I had my guide/driver with me, else it would have been confusing.
Unfortunately the day was overcast this day, but it appeared to keep the numbers down (why, I never figured out). From the 'Garganta del Diablo' (Devil's throat) station, its a bit over a km walking on a solid steel mesh walkway - wheelchairs were on it.
Approaching the business end, fine misty spray comes up on the left, but the major action is to the right. Actually what is going down the Devil's gullet here is just stupendous.
The view down the chasm - the Brazilian tower can just be seen in the middle; on the right - down the throat!