By road, Mercedes, Uruguay and Sierra de La Ventana, Argentina are about 523 miles (842 km) apart, or roughly 10 h 14 min of driving. You cross from Uruguay into Argentina at about mile 21, at the Gualeguaychú–Fray Bentos bridge.
Full advisory: Uruguay, Argentina. Advisory issued: Uruguay July 28, 2026; Argentina July 10, 2026; checked October 10, 2026.
On the roads, the State Department says:
- Uruguay: “Traffic fatalities are high in Uruguay.”
- Argentina: “Drivers in Argentina tend to be aggressive, especially in Buenos Aires, and often ignore traffic regulations.”
| Total distance | 523 mi (842 km) |
|---|---|
| Time at the wheel, no stops | 10 h 14 min |
| Main roads, in order | RN136 → RN14 → RN12 → RP6 → RN205 → RP51 → RN226 → RP76 → RP72 |
| Border crossing | about mile 21, Uruguay → Argentina (the Gualeguaychú–Fray Bentos bridge) |
| Regions on the route | Soriano, Río Negro, Entre Ríos, Buenos Aires |
| Fuel estimate (car at 25 mpg) | about 20.9 gal; actual use varies by vehicle and traffic |
| Stops listed below | 4 |
Crossing from Uruguay into Argentina
The route crosses at about mile 21, at the Gualeguaychú–Fray Bentos bridge, from Río Negro into Entre Ríos. Plan on two checks on each side: immigration for your passport and customs for the car.
| Entering Argentina (U.S. citizens) | No visa needed for visits of 90 days or less. Passport: must be valid when you enter; leave a blank page for the entry and exit stamps. |
|---|---|
| Driving in Argentina | A valid U.S. license usually works; an International Driving Permit is recommended. |
| Entering Uruguay (U.S. citizens) | No visa needed for visits of 90 days or less. Passport: must be valid for 6 months beyond your arrival date. |
| Driving in Uruguay | You can drive on your U.S. license. |
| The car, entering Argentina | Argentine customs (ARCA) registers the car's temporary entry. Bring the title or registration, liability insurance valid in Argentina and, if you don't own the car, a power of attorney signed before a notary. A rental car needs the rental company's MERCOSUR circulation authorization (ACM), and the company must be registered with Argentine customs. |
| Rental car | Cross only if the rental company authorizes it in writing and gives you the papers for the border; ask before you book. |
Sources: U.S. State Department, Argentina (updated July 16, 2026); U.S. State Department, Uruguay (updated August 13, 2026); ARCA (Argentine customs). Checked October 10, 2026; rules change, so confirm before you go.
How the Mercedes to Sierra de La Ventana drive plays out
RP51 (144 mi) and RN205 (74 mi) carry about 42% of the 523 miles. The first 21 miles are in Uruguay; the last 502 are in Argentina. It runs through 4 regions: Soriano, Río Negro, Entre Ríos, Buenos Aires. None of the 4 stops below is right on the road, so plan each as a short side trip.
Road-by-road breakdown: Mercedes to Sierra de La Ventana
| Road | Route miles (from–to) | Length, mi | Region |
|---|---|---|---|
| local roads | 0–19 | 19 | Soriano, Río Negro |
| connecting roads | 19–21 | 2 | Río Negro |
| RN136 | 21–41 | 20 | Entre Ríos |
| local roads | 41–47 | 6 | Entre Ríos |
| RN14 | 47–83 | 36 | Entre Ríos |
| RN12 | 83–130 | 47 | Entre Ríos, Buenos Aires |
| RP6 | 130–203 | 73 | Buenos Aires |
| RN205 | 203–277 | 74 | Buenos Aires |
| connecting roads | 277–281 | 4 | Buenos Aires |
| RP51 | 281–367 | 86 | Buenos Aires |
| RN226 | 367–385 | 18 | Buenos Aires |
| RP51 | 385–443 | 58 | Buenos Aires |
| RP76 | 443–514 | 71 | Buenos Aires |
| RP72 | 514–523 | 9 | Buenos Aires |
- Mile 3 of this route: Soriano → Río Negro (region line)
- Mile 21 of this route: Río Negro → Entre Ríos (international border)
- Mile 114 of this route: Entre Ríos → Buenos Aires (region line)
Places worth a stop between Mercedes and Sierra de La Ventana
- Nature and outdoors: Ciervo de los Pantanos National Park (mile 140)
- Museums and history: Gualeguaychú Cathedral (mile 42), Our Lady of the Rosary Cathedral, Azul (mile 362)
Frigorífico Anglo del Uruguay
Part of a UNESCO World Heritage landscape inscribed in 2015, the old Anglo meatpacking plant stands on the Uruguay River at Fray Bentos, where frozen meat shipments began in 1924.
Gualeguaychú Cathedral
St. Joseph's Cathedral, also called Gualeguaychú Cathedral, serves as the cathedral church of the Roman Catholic Diocese of Gualeguaychú in Argentina.
Ciervo de los Pantanos National Park
Marsh deer give their name to Ciervo de los Pantanos National Park, a Ramsar Site in Campana, Buenos Aires province, where waterbirds are abundant.
Our Lady of the Rosary Cathedral, Azul
Azul Cathedral, dedicated to Our Lady of the Rosary, is a Gothic-style Catholic church in Azul, Buenos Aires Province, inaugurated in 1906.
More drives to Sierra de La Ventana
- Viedma to Sierra de La Ventana
- Balneario El Cóndor to Sierra de La Ventana
- Puerto Madryn to Sierra de La Ventana
- Rawson to Sierra de La Ventana
- Tigre to Sierra de La Ventana
- Buenos Aires to Sierra de La Ventana
More drives from Mercedes
- Mercedes, Uruguay to Colonia del Sacramento
- Mercedes, Uruguay to Alejandro Gallinal
- Mercedes, Uruguay to Cabo Polonio
- Mercedes, Uruguay to Chuy
- Mercedes, Uruguay to Río Branco
- Mercedes, Uruguay to Tigre, Argentina
Continue Your Adventure
Frequently asked questions
How long does it take to drive from Mercedes, Uruguay to Sierra de La Ventana, Argentina?
About 10 h 14 min of driving without stops, over 523 miles.
What is the driving distance from Mercedes, Uruguay to Sierra de La Ventana, Argentina?
About 523 miles (842 km) on the Wayro route. Other map services may show a few miles more or less, depending on where they start and end in each city.
Where does the Mercedes to Sierra de La Ventana drive cross the border?
At about mile 21, from Uruguay into Argentina, at the Gualeguaychú–Fray Bentos bridge.
What do U.S. citizens need to drive from Mercedes into Argentina?
No visa needed for visits of 90 days or less. Passport: must be valid when you enter; leave a blank page for the entry and exit stamps. A valid U.S. license usually works; an International Driving Permit is recommended. (U.S. State Department, updated July 16, 2026.)
What does the U.S. travel advisory say about the Mercedes to Sierra de La Ventana drive?
The U.S. State Department rates Uruguay Level 2: Exercise Increased Caution; Argentina Level 1: Exercise Normal Precautions. Read the full advisory before you go.
Which highways go from Mercedes to Sierra de La Ventana?
In order: RN136, RN14, RN12, RP6, RN205, RP51, RN226, RP76 and RP72. The road-by-road table above shows the route miles for each one.
Where can you stop on the way from Mercedes to Sierra de La Ventana?
Closest to the road: Frigorífico Anglo del Uruguay (industrial heritage site, mile 19, 5 mi from the route); Gualeguaychú Cathedral (cathedral, mile 42, 1 mi from the route); Our Lady of the Rosary Cathedral, Azul (cathedral, mile 362, 2 mi from the route). All stops are described above.
How we put this guide together
Wayro calculates the route from OpenStreetMap road data; mile numbers are positions along this route, not highway markers, and "from the route" distances are straight-line, so the real detour depends on access roads. Stops are chosen from parks, natural sites, museums, historic sites and attractions close to the route: at least one strong stop for each stretch of the drive, then the best-known places nearest the road, up to nine in all. Places that are closed, private or not open to visitors are removed. Place descriptions are written by the Wayro team from official park, museum, tourism and government websites and other published sources. Safety levels and entry rules were checked against the U.S. Department of State on October 10, 2026. Conditions change, so check the linked sources before you travel.
Route data © OpenStreetMap contributors.