Isla Martín García

Isla Martín García is a knob of ancient bedrock in the Río de la Plata, geologically part of the same shield as Uruguay and utterly unlike the muddy delta islands around it. Its position at the meeting of the Paraná and Uruguay rivers made it strategically important for centuries, and it served as a fortress, a quarantine station, a naval base and a prison that held several Argentine presidents in the twentieth century. It is now a provincial nature reserve, with subtropical gallery forest, more than two hundred bird species, and the crumbling remains of its institutional past: the old theatre, the bakery, the naval buildings and a cemetery. Day trips from Tigre include a guided walk, and a few people stay overnight.

What you actually see

• The historic buildings - old naval structures, theatre, bakery and cemetery.
• The gallery forest - subtropical woodland with rich birdlife on the trails.
• The rocky shore - bedrock beaches unlike the delta's mud islands.
• The river crossing - the long catamaran ride through the delta and estuary.

When to go

October to April for warm weather and calmer water; trips are cancelled in strong winds at any season. Boats run on fixed days, usually a few times a week, and must be booked ahead. The island can be very hot with limited shade in midsummer.

Honest expectations

The round trip takes most of a day with roughly six hours on boats for a few hours on the island. Services on the island are minimal, with one or two simple eating places. Cancellations due to weather are common.

Nearby

Tigre is the departure point; the Uruguayan coast lies close across the water.