Incredibly wide border crossing
Rio de la Plata, the river separating Argentina from Uruguay, is so wide that it takes two hours to cross by ferry.
That’s not even to get you down river to Montevideo. The ferry simply crosses from Buenos Aires to Colonia, the closest major city in Uruguay. From there, it’s still a 2.5 hour bus ride on to Montevideo.
Luckily, it’s a luxury ferry with a store, an arcade, two restaurants, a bar, and other amenities. There are even elevators if taking the stairs between decks is problematic.
Buquebus Ferry
The bus is not as luxurious as other buses which travel throughout South America. However it is comfortable and has reclining seats.
The ferry terminal has an unusual dual immigration system in which officials from both countries sit side-by-side at the same desk.
When crossing from Argentina to Uruguay, first the Argentine official will check your documents. He’ll stamp your passport to acknowledge that you are leaving the country.
Then he’ll pass you on to his Uruguayan counterpart sitting right next to him who will check and stamp your documents, admitting you into Uruguay. All of this takes place while you are still on Argentine soil, in the departure terminal for the ferry.
Presumably, the process is similar when traveling in the reverse direction.