An agency on Manuel de Lobo in the old town, run by people who live here, covering Colonia del Sacramento and the wine country up at Carmelo. Their own summary — "personas reales creando experiencias reales" — is doing some marketing work, but the useful part is that they guide in Portuguese as well as Spanish and English, which matters in a town that fills with Brazilians.
They are the practical answer to Colonia's particular problem: the barrio histórico is tiny and the ferry crowds move through it in a block, so the value of a guide is knowing which hour to be where. They also run the trip north to Carmelo, which is otherwise awkward without a car.
Bookings go through WhatsApp on the number below.