North of San Jose and Brava, the Transect Trail is 40km trek through the rugged wilderness of the Braulio Carrillo National Park. The Transect Trail is typically a 4 day south-to-north journey along the parks western boundary. This rarely used trail was originally a horse pack route running from the Barva Ranger Station in the south to the Magsasay Ranger Station in the north. Along the way, there is about 2,870m of elevation drop. This is a difficult to follow route, has numerous turnoffs, and a guide is a necessity. There are some shelters along the way.
To reach the southern Barva Sector Ranger Station from San Jose, you will need a 4WD vehicle. Next, head to Heredia. From Heredia, you will need to find the correct road to the town of Barva (hint: the road is near a very old church in the town center -- you might want to ask someone which road is the right one). Once you are in the town of Barva, continue on the paved road towards Sacramento. There are several unsigned turnoffs. After Barva, make sure to take the first left, then the next right and then the next right turns. At the fourth fork in the road, turn left heading up hill to the village of Porosati. Continue on the rough pavement to the next fork in the road and turn left. At the next intersection, there should be a sign directing you to the park which is about 8km away. The final 4km are unpaved, very rough road.
The phone number for Barva Sector Ranger Station is (506) 261-2619).
In addition to the Transect Trail, there are many other popular trails starting from the Barva Sector Ranger Station. The Sendero Botarama trail is a 1.6km route that takes about 2 hours to hike. It follows an abandoned dirt road to Rio Sucio. The Sendero La Botella trail is a 2.8km route along La Patria Canyon past several waterfalls. There is a side journey at the 2.km point that may be signed, which leads another 3km to Rio Saguiluela, but this route is not well maintained (ask a ranger if you are interested). The Lago Barva Trail is a 3km hike that typically takes about 2.5 hours. It follows the road that you drove in to the ranger station on. After about 2km, the road ends and the trail heads off to the right. The trail goes another 1km to Lago Barva, which is a small body of water in an extinct volcanic crater.
To reach the northern Magasay Ranger Station from San Jose, head to Alajuela. In Alajuela, head north on Highway 126 for 38km. Just past the town of Bosque but before La Virgen, turn right on a dirt road. Pretty quickly, there is a fork in the road. At the fork, veer left and continue for 10km to the Magasay Ranger Station. Note: a high-clearance 4WD vehicle is required to get to the Magasay Ranger Station. During any heavy rain, it may be impossible to get to the Magasay Ranger Station.
Here are some basic notes on driving in Costa Rica for the tourist. There is a myth about the quality of the roads and of VW bus sized pot-holes. This may have been true years ago, but on the main routes, this is no longer true. With that said, there are still numerous challenges for first time drivers in Costa Rica. First, do not expect much out of so-call “highways”, like the InterAmerican Highway. The fancy name makes the uninitiated think this is a major 4 lane divided, restricted access road. Well, yes, about 1% is. The rest is two lane (marginally), undivided, rural roads with tons of traffic constantly stopping, turning, passing or driving slowly. Like every other road in the country, you can expect to see on the road numerous unexpected cows, cyclists, pedestrians, bus stops, school crossing zones, dogs, mud slides, police check points, unannounced one-lane bridges, missing manhole covers, and, of course, a never ending stream of semi-trucks driving erratically fast. What you do not find on any roads is much signage. There are infrequent signs indicating the distance to the next town, and even more infrequent are road names or numbers (if at all), including even within major towns. To make matters worse, signs that used to exist are disappearing due to deterioration or theft. Also, do not expect drivers to use their head lights, even in a heavy rain shower, unless it is really dark. This makes passing in rain a game of roulette since you can't see the oncoming traffic. Speaking of dark, do not drive at night since the roads in some areas can be ruled by those under the influence of alcohol.
If you have to drive through San Jose, make sure to do it at dawn to avoid the horrendous traffic all day long, including weekends. Keep in mind several maps show highways passing through San Jose. This is not true. They end abruptly on the outskirts of town and you have to slug it out in a crazy stop-and-go traffic and many unmarked turns to get to the other side all day long. There are unsigned so-called by-pass routes around San Jose, but finding them can be a challenging game of trial-and-error, and they are only marginally better.
If you have to drive on the Nicoya Peninsula, you can expect to find generally better roads with better signage. However, there are numerous unmarked eroded road sides, especially over stream culverts. Do not drive at night. Watch out for the iguanas sprinting across the road.
A GPS unit can be helpful when navigating roads, however, the maps in Costa Rica were created using a special map datum. This datum is not usually available on GPS units but the road base maps were created with it. Therefore if you use the default WGS84 datum with a base road map on the GPS unit, you will always show a position being about 0.5 miles to the north of the road base map.
When picking up a rental car, make sure to check all the tires for wear, check the spare tire pressure, check the tire jack, and make sure to test the lock on the spare tire. It would be wise to quickly purchase a can of Fix-A-Flat.
Overall, Braulio Carrillo National Park - Transect Trail is the 4th most popular hiking trail of all 20 hikes in Costa Rica.