The first destination will be the large town of San Isidro de el General located to the west of the peak and national park. To reach San Isidro from San Jose, take one of the hourly (seven days a week) buses to San Isidro from the bus terminal at Calle Central and Avenida 22. It's a three hour ride.
From San Isidro, you must take another bus to San Gerardo de Rivas. The bus takes two hours and leaves at 5 AM and 1 PM each day. Get off the bus at the Parue National Chirripo ranger station.
Below the timberline, the trail passes through lush rainforest.
The first day is a long one. It is recommended that you arrange permits the day before in order to get an ealy start the next morning. At the very latest, a 6 AM (earlier is better) start is recommended. It is much better to do the first section of the trail in the cool of morning as it can be very hot later in the day. Make sure you carry enough water along for the first 7.5 kms as none is available. Most of the hostels and lodges can arrange transport early in the morning to the trailhead. It's about 2 kms from the ranger station to the trailhead.
The first day to the Base Crestones (hut) is 14.5 kms with 2200 meters elevation gain. From the ranger station, follow the signs to the trailhead. The trail immediatly begins its steep climb to the "Water Ridge". You will pass some cleared land for cattle grazing before you enter the rainforest. Keep an eye out for Quetzels (birds) along the way. After 7.5 kms of steep walking, you will reach "Water Ridge" which is a picnic area and a water tap. Stock up with water here, as there is no more available until you are near the Base Crestones. Keep and eye out for both spider and white face monkeys in the area; we saw several just below the lunch area on our return trip.
After enjoying a well deserved break, continue of the steep trail. The three uphill sections have names. The first is Cuesta de Agua (Water Hill), the second Monte Sin Fe (mountain of no hope), and the third is La Cuesta de los Arrepentidos (repentance hill). The first and last hills are the longest and steepest. At the top of Monte Sin Fe, you reach the Paramo. A few kms after that you will cross a stream on a bridge. From here its one long steep section to the Base Crestones Hut.
After spending the night in the hut, follow the trail that crosses the Rio Talari just east of the Base Crestones hut. Just after the stream crossing, you will reach another trail junction. Take the left trail posted for Crestones. The trail climbs steeply up to the base of the Cestones after 1.8 kms from the hut.
The Crestones themselves are a technical rock climb by all routes. The granite is very solid and there appear to be several 5th class routes available. The highest “summit” of the Crestones can be climbed by someone with basic rock climbing experience and can be done without a rope. There are two very short pitches of 5.4 YDS/III UIAA (Fabienen Cordoba info).
The more difficult “summit” of the Crestones is a rock tower known as La Aguja. It is rated 5.12YDS/VIII UIAA.
Once the base of the Crestones is reached, the trail continues climbing steeply to Cerro Terebi. Cerro Terbi is 2.3 kms from the Base Crestones hut. The view is fantastic. On an exceptionally clear day (rare) you can see both oceans. You are also treated to seeing many glacier carved peaks including Chirripo, the highest peak in Costa Rica. The view down the glacier carved valley is spectacular as well.
There is an alternate and less used route down from Cerro Terbi. Follow the trail along the ridge north. After a short ways, the trail drops very steeply to the west and follows a very steep path down to the Valle de los Conejos (Rabbit Valley). At Rabbit Valley, there is a four way junction. In addition to the trail you're on, there is a trail that heads straight (north) to Cerro Chirripo, left (west) to the Base Crestones hut, and east (right) to Laguna Ditkebi.
If your feeling up to it, you can also climb Chirripo on the same day. This requires spending another night at the Base Crestones. Since it is assumed that most people climbing Crestones-Cerro Terbi also plan to climb Cerro Chirripo, spending at least two nights at Base Crestones hut is recommended. There are other peaks in the area to climb as well (see the page on Cerro Ventsqueros, and there are more peaks to choose from), so some may want to spend a third night. The trip can be done in two long days if you plan on just climbing Crestones-Cerro Terbi.
Terbi is the peak on the right, as seen from the approach trail to Chirripo.
A good pair of boots, warm clothing, rain gear, and a sleeping bag are needed to climb Cerro Terbi. A full rack of rock climbing gear as well as ropes are needed for those attempting to climb most routes on the Crestones, though one route can be done reasonably without a rope, if you are an experienced climber.