Costa Rica is a small country (size about that of West Virginia; population half of New York City’s) with a great deal to do and see. In a bit more than two January weeks, we successfully exhausted ourselves.

We began with one of the country’s rain forests. The place has an ingenious aerial tram: outbound near the valley floor, return up in the canopy, where much of the wildlife hangs out. We saw a few furry animals and a lot of birds. Also a procession of small leaves crossing the trail. Actually they were being carried by a long line of industrious leaf-cutter ants, who use them obscurely as a nest.

Next two days rafting the Pacuare--our first such venture since the Rio Grande.We were a considerable crowd: five crafts with five or six tourists each, plus assorted kayakers who attached themselves to us as egrets to cattle. We had to learn a few commands, such as “back right!” The trick is that while the right side backpaddles, the left must continue its forward strokes. Also “lean in”--which means that the raft is about to flip over. Rapids are classed from one to six, in rank of difficulty. We got up to four, which was quite high enough. An American family had come to join the fun, but two of them were two big for the Costa Rican kayaks.

We spent the night at the lodge of the rafting company, Rios Tropicales. It reminded us of the place where we stayed on the Mekong, in Laos. There was just enough electricity to display still photos of the day’s action, showing most of us terrified at the prospect of tipping over. The next day the photos were for sale. Very business-like. Also humid and atmospheric.

The Pacuare is a gorgeous river, but even in conservation-minded Costa Rica it was under threat from a government plan for a massive hydroelectric dam. The plan was, however, rejected in 2005.

One the way back to the capital, San Jose, the bus blew a tire. We stood outside in the rain while it was changed. [My last three flat tires have been in Nepal, Ecuador, and Costa Rica. Is this significant? I do not count the subsequent episode in South Africa, which was our doing.]

Happy New Year! Then our one internal flight, 45 minutes south to Palma Ur. The airline, Sansa, has a reputation for informality, but the plane, a single-prop Caravan, behaved perfectly properly. Next, a bumpy auto ride through banana plantations to the Sirpe River. The fiberglass canopied boat that took us to the Pacific ran on a 75 m.p.h. Yamaha outboard. It may have had life jackets, oars and a spare motor, but they were not visible. The river flowed calmly through mangrove swamps on its way to Drake Bay (pronounced dra-cay, after the famous British sailor, Sir Francis Dracay). Once we hit (that’s what it felt like) the ocean, things roughened considerably. But it was nothing compared with the landing. Technique as follows: boat turns head-on to shore. Motor revs to max. Boatman shouts “Hold on!” Boat roars onto the beach and up the sand. Really wakes you up.

We had arrived at Poor Man’s Paradise, a steamy little bungalow colony. Among the guests were Cassandra, a Mexican-American actress turned law school student and her Vietnamese boyfriend, Tai; and a Montanan who had been drilling oil in Nigeria and Turkey during the times I was there. We all met in the dining room where we were invariably offered gallo pinto. It means spotted horse, and it is rice with beans. There is a lot of gallo pinto in the country. (We did have some very good meals in the San Jose area, but food is not a compelling reason to visit Costa Rica.)

Poor Man’s P was a funky place, run in part by a diminutive Irishwoman who turned out to be Belgian (she did learn her English in Ireland). Like many such establishments, it provided electricity for only a few hours each day. The bungalows were very Somerset Maugham, but having the roof leak during one of the heavier rains was carrying mood-evocation too far. The ocean was swimmable, with due caution, beautiful and warm. Our guided visit to the adjacent Parque Nacional Corcovado, “some of the wildest yet most accessible rain forest in Costa Rica,” showed us numerous birds and a howler monkey hanging by its tail. Unhappily, our scheduled snorkeling trip to the offshore Cano Island was canceled on account of rain, of which we had a great deal.

After three nights we boarded the boat, which had been rolled and shoved back into the ocean, and were driven to the Rancho La Merced. We hadn’t known what to expect. What we found was a small home with a boy of about eight. He spoke little English, but assured us that his father was more proficient. We laid out our wet clothes and awaited developments. When father appeared, he looked, as our itinerary had promised, like a rancher. His English was about as good--that is, as bad--as our Spanish. The conversation, such as it was, came around to caballos. Luckily for us, the horses were docile and understood a little English (“stop”). We rode them up some green hills to a lovely waterfall.

Lunch was with father and family in the farmhouse kitchen. Although the house was modest, it was electronically upscale. The kids played video games (Italy vs. Brazil in soccer). After lunch we horsebacked to the beach. An entire mile of shoreline was empty, except for us: Susan’s adolescent dream of galloping in a deserted beach come true.

The next day we tried yet another mode of transportation: the tourist kayak, long and reassuringly stable. We plied some creeks to find more exotic birds and furry creatures, which had been provided by our travel agency. Thence to another lovely deserted beach.

Continuing north, we spent the next night at Talari Lodge, run by a Dutch/Costa Rican couple. Very European, with wine and classical piano. We were now ready, we hoped, for the big challenge: the ascent of the country’s high point, Cerro Cherripo, 12,500 feet. (In Central America, only Guatemala has higher summits.) It’s not a technical climb, but it does go a long way up, an intimidating prospect for us old folks. We awoke at the next morning. (Early starts were a depressingly feature of this trip.) We were expecting younger companions, but it was a shock to find a van filled with teenagers. Dawn revealed them to be close to 30, however: Candida and Theresa from England and Eric, French-Canadian.

How to describe the Chirippo trail? Just a walk, one might say; horses manage it without protest. It’s never really steep. But it is long, often muddy, and unrelentingly up. It starts at about 1500 meters; the refugio is at 3400 (sounds worse in feet: multiply by 3.3). We were carrying day packs, trek style; the horses had the rest. We passed through seven distinct vegetation zones, but by zone three or so I was puffing too hard to notice. (I did observe when we reached the rain forest, thanks to the clouds.) The higher we went, the cooler it became, and the slower I moved. The landscape turned barren, the result of a huge 1992 forest fire.

The refugio was a bleak but welcome sight. It looked like a high-altitude cell block, but it had a roof and rooms with two bunk beds each. We had arrived at 3:30. Our trail time (not bad) had been eight hours. Our splendid guide, Noel, produced sleeping bags, into which we crawled. The (indoor) temperature was somewhere in the forties. The place resembled a hut in the Alps, with communal cooking facilities and some electricity--just how much depended on the sun, because it was due to solar power. There were at least forty other guests. We ate dinner while wearing hats and gloves. Bedtime was 8:00 p.m.

The following morning, after a gratifyingly late start to permit the rain to clear, we climbed the mountain. I had discovered, with sobering satisfaction, that I was by two years Noel’s oldest client ever. So I proceeded at an age-appropriate pace. The summit, once attained, did briefly permit the heralded view of both the Caribbean Sea and Pacific Ocean. Also a vista of lakes and peaks that looked (but were not!) higher than ours.

Back, all too early, at the chilly refugio, we retreated to our sleeping bags and tried to read. I recommend bringing an account of people who are more uncomfortable than you are. Our Harvard climbing trips included Apsley Cherry-Garrard’s celebrated Worst Journey in the World (Scott’s Antarctic expedition; penguin eggs). For Costa Rica I took Three Came Home, Agnes Newton Keith’s harrowing account of being a prisoner of the Japanese in Borneo during WWII. Our reading was interrupted by two guests assigned to the empty bunks in our room. They must have thought us too sour and messy to room with. They seized the upper mattresses and fled, though not before dropping a mattress on Susan. She did not like this.

We had three nights at the refugio. Eric left and was replaced by Luke, an Australian zoologist preparing a Lonely Planet wildlife guide. Our return to the civilized world was fairly fast, but muddy. This made the subsequent soak in an isolated hot spring all the more luxurious.

Recuperation time. We were driven up a twisty and dangerous fog-bound road that we later learned was part of the Pan-American Highway. It featured uphill curves and was menaced by enormous trucks. Our Costa Rican driver was unperturbed; she turned onto an even steeper, intermittently paved track down to Savegre Mountain Hotel. Electricity and comfort. We washed our filthy clothes and relaxed.

The following morning (early, of course) our guide Walter took us to find the famed resplendent quetzal. This is an amazing bird, even by the gaudy standards of Costa Rica. It is three feet long (half tail) and red, white and bright green. A number of them had been apprised of our interest and obligingly flew around an avocado tree for nearly an hour. They look even better through a telescope.

Our next night was at the Hotel Bougainvillea, a few miles north of San Jose. We were back in the world of television and the internet. Here for the only time we joined a real tour, “Highlights,” which makes a daily bus circuit of the country to the near north. We stopped at waterfalls and a volcano. Unfortunately, as is often the case, the crater was scarcely visible in the cloud.

Lunch was at the Selva Verde Lodge, where we had booked two nights instead of staying with the tour. We were back in the rain forest world. Bird were abundant, including toucans, which with their imposing beaks fed on bananas set for them.

The Lodge, a major Elderhostel destination, provided many facilities. We swam in the Sarapiqui River, a hundred yards from our room (DO be careful of the current). Susan made two equine expeditions, and we both went rafting. With our now vast experience, we were not intimidated--until we reached the put-in, which entailed an alarming scramble down a nearly vertical mud embankment.

The flight home was fine, except that airport security confiscated my can of insect repellent.