East of Turrialba, Highway 10 continues past CATIE two kilometers to a Y-junction: the main highway descends to Siquirres and the Caribbean after switchbacking steeply uphill to tiny Turrialtico, eight kilometers east of Turrialba. The branch road off Highway 10 leads southeast to the valleys of the Río Atirro and, to the east, Río Tuis.

One kilometer east of CATIE you cross the Río Reventazón (Exploding River). The river, which begins its life at the Lago Cachí dam, has been dammed about two kilometers upstream of the bridge to create the 256-hectare (450,000-cubic-meter) Lago Angostura.

The Proyecto Hidroeléctrico Angostura (Angostura Hydroelectric Project), the largest hydroelectricity-generating plant in the country, began humming in July 2000. Below Lago Angostura, the river cascades down the eastern slopes of the Cordillera Central to the Caribbean plains. On a good day it serves up Class III–IV rapids.

Hacienda Atirro dominates the flatlands of the Reventazón and Atirro Rivers south of the lake. The sugarcane-processing factory can be visited in harvest season as part of a plantation tour; you can book through Hotel Casa Turire (tel. 506/2531-1111, www.hotelcasaturire.com). The Beneficio Grano de Oro (tel. 506/2531-2008, www.goldenbean.net) also welcomes visitors for the Golden Bean Coffee Tour.

Nearby, Criadero Aura Turrialba (tel. 506/2506-7513, 10 a.m.–5 p.m. daily, $2) is a macaw-breeding facility that welcomes visitors. It had 14 green macaws and 65 scarlet macaws at last visit. The original birds were all acquired from MINAE and were either injured or were illegal pets confiscated from their owners.

At Tayutic: The Hacienda Experience (tel. 506/2538-1717, www.haciendatayutic.com, 8 a.m.–5 p.m. daily, $50 adults, $45 students, $30 children) you can witness rural traditions being kept alive. This faux colonial village has coffee, macadamia, and sugarcane plantations to each side, with demonstrations of the production and processing of each crop. It’s a fun learning experience, especially for kids. The turnoff from the Siquirres road is at Boveda, about two miles west of Pavones.

Serpentario Viborana (tel. 506/2538-1510 or 506/8882-5406, viborana [at] racsa [dot] co [dot] cr, 9 a.m.–5 p.m. daily, $10 one hour, $15 two hours) is a serpentarium near Pavones, beyond Turrialtico. About 100 snakes are displayed in cages, including a large boa pit. A visit begins in the open-air lecture room and trails lead into the forest.

With a 4WD vehicle, you can descend the gnarly track to the community of Bajo del Tigre, four kilometers from the highway; the turnoff is about 15 kilometers north of Turrialtico. Here, Ríos Tropicales has funded a community project that now features a serpentario (snakes) and orquideario (orchids) at the home of Juan Alberto González (tel. 506/2554-1536, 7 a.m.–5 p.m. daily, by donation). There is a butterfly farm nearby.

Hotel Casa Turire (tel. 506/2531-1111, www.hotelcasaturire.com), on the south shore of Lago Angostura, offers horseback tours, mountain biking, and other activities.

Hotals and Restaurants

Finca Monte Claro B&B (tel. 506/2538-1383,www.fincamonteclaro.com, $15 pp with breakfast), 100 meters east of Turrialtico Lodge, is set on an organic coffee farm and offers unique accommodations. A former sheepfold on piles has been converted into an open and shaded deck where you can sleep with the elements on simple beds with mosquito nets. You get views of both the volcano and town of Turrialba, plus use of a kitchenette and shared bathroom and toilets. There is no electricity. Horseback tours are available.

Turrialtico Mountain Lodge & Restaurant (tel. 506/2538-1111, www.turrialtico.com, $52–68 s/d low season, $58–75 s/d high season), amid landscaped grounds with views over the Reventazón Valley, has upgraded its 14 rooms and turned them from ugly ducklings into modern charmers. The restaurant (7 a.m.–10 p.m. daily) offers seafood (like sea bass in garlic, $12), tenderloin ($10), and local fare, enjoyed in a newly hatched ambience that combines rusticity and elegance. Rates include breakfast and taxes.

Nearby, and also enjoying a ridge-top view, the deluxe Hotel Hacienda Tayutic (tel. 506/2538-1717, www.haciendatayutic.com, $295–395 s/d) combines a cozy rusticity with sumptuous furnishings in its lodge, as well as spectacular views. Although vastly overpriced, each delightful room is individually themed. All come with terra-cotta floors, WiFi, satellite TV, and coffeemaker, plus spacious bathrooms. It has a spa, plus tours.

I’m smitten by the Hotel Villa Florencia (tel. 506/2557-3536, www.villaflorencia.com, $118–226 s/d year-round), which occupies a hilltop overlooking cane fields on the west side of Lago Angostura. The former deluxe mansion offers 11 nicely furnished rooms (one for travelers with disabilities, one a suite) and boasts lots of redbrick and terra-cotta tile, plus river stones and gleaming hardwoods. The lovely suite has a king bed, flat-screen TV, and a gorgeous half-moon bathroom with whirlpool tub and separate shower. It’s a good base for bird-watchers. The restaurant and swimming pool were being completed during my visit.

The most outstanding hotel for miles is Hotel Casa Turire (tel. 506/2531-1111, www.hotelcasaturire.com, $120–350 s/d low season; $135–350 s/d high season), on the south shore of Lago Angostura, about 15 kilometers southeast of Turrialba. Relaxing and romantic, this hotel is infused with a Georgian England motif and is justifiably a member of the Small Distinctive Hotels of Costa Rica. You sense the sublime the moment you arrive via a long palm-lined driveway and enter the atrium lobby of the plantation property, with its colonial-tiled floors, Roman pillars, and sumptuous leather sofas and chairs. The 12 spacious, lofty-ceilinged rooms have direct-dial telephones, WiFi, and flat-screen cable TVs.

Bathrooms received a stylish remake in 2011, with heaps of marble. The four suites now boast a gorgeous aesthetic, and have french doors opening onto private verandas; the master suite has a whirlpool tub. A wide wraparound veranda opens onto manicured lawns and a small figure-eight pool and sunning deck. There’s an eco-farm (with water buffalo) and a stable, plus a spa, horse-and-carriage rides, and a fitness trail (with guide and prior request only).

This is also the place to treat yourself to a meal: Culinary treats (using organic produce from the hotel’s own gardens) include curried banana soup ($6), dorado with orange sauce and almonds and mashed potatoes ($12), and hot chocolate cake with flambéed bananas ($5). It boasts a coveted four CST (Certification for Sustainable Tourism) leaves.

For irresistible rusticity you can’t beat Bella Vista B&B (tel. 506/8915-9643, www.haciendabellavistaturrialba.com, $60 s or $80 d low season, $80 s or $100 d high season), where six thatched wooden cabins with raised roofs are almost ascetic in their furnishings. But you do get hot water, cable TV, and telephone. It has a lovely restaurant and bar and the overall aesthetic is divine. Trails lead to a river with natural pools.

Getting to Lago Angostura

Buses (tel. 506/2556-4233) for Siquirres depart Turrialba from Avenida 4, Calle 2, hourly 5:30 a.m.–6:30 p.m. daily; ask to be let off at Turrialtico.