Yes, you're missing the Osa Peninsula which is amazing - best wildlife that we've ever seen. Bosque del Cabo has a nice video on their website so you can see what the area looks like. It's an excellent place for birdwatching. We saw scarlet macaws and toucans there. Tortuguero is pretty neat as well, lots of wildlife and a canal-based environment. We loved Tortuga Lodge. Monteverde is great for birding too and offers a cooler cloud forest environment. Use Sansa or Nature Air for in-country flights to the Osa.

Thank you, Volcanogirl. I figured you would point us to the Osa Peninsula. I am busy rereading the guide book now so that things begin to take shape in my mind.

Any suggestions as to how much time to spend in each area?

PJ, your agenda, interests and time frame are very similar to ours. Our trips to CR 93, so far), included a night or two in or near San Jose, where we left our luggage in between legs, and about 3 destinations. Last time we spent 8 days at BdC. It really is all volcanogirl describes, a very special place.

For variation and fantastic birdwatching in a relatively non-touristy environment,, we liked Savagre Lodge in Cuerte del Muerte. Hoping it hasn't changed, as it looks as though it's gotten a bit fancier than the small, homey spot that it was. Fantastic guides!

Hi PJ, I agree that the Osa and Tortuguero are wonderful, but you might consider La Selva or Selva Verde if you are interested in birding. You won't see as many birds in the Rincon de la Vieja area, but it is still a nice area to visit. There are three places to stay up there, Borinquen is much more relaxed. If you need help putting things together, please let me know as I can offer private transport between point A and Point B if that is the route you decide to go. The English speaking drivers offer a wealth of information around the country and you would travel at your own pace stopping for bathroom breaks and photos when you see something interesting. I certainly wouldn't spend less than 3 days in most the of areas, but you could probably do only 2 nights in Tortuguero and be all right. The best way to get from Monteverde-Arenal is via lake not on the bumpy road

The Sarapiqui area may have the best birding in the country as well as great overall wildlife sighting and ecoutours, has plenty of reasonably priced ecolodges.

The best areas we experienced for birding/wildlife were:

1) Osa Peninsula (Sirena station, Corcovado National Park)
2) Sarapiqui area
3) Arenal Observatory Lodge (with trip to Cano Negro)
4) Tarcoles area (Tarcoles river tour, Carara national park)

Monteverde was very good for birds but not so much other forms of wildlife, and while Manuel Antonio was great for mammals but lousy for birds.

Also, Curu reserve in the Nicoya peninsula is worth seeing if you're in the area.

If you end up doing both Arenal and Monteverde, the Jeep Boat Jeep with Desafio is a good way to go - pretty affordable and saves you time on that bumpy road.

Sarapiqui is fantastic!!! I do love the cloudforest also, as its a wonderful contrast. Tortuguero too. You simply can't go wrong.Look up all of the recommended areas, and see which appeals.

Regarding transportation, Interbus or the like is easy and cheap. Some folks prefer private transport. We prefer taking the short flight to the Osa though, over the long, hot drive.

PJ, yes, since you said hiking and wildlife, the Osa is numero uno in my book. We also love the Cano Negro tour out of the Arenal area, but we've only done it during rainy season. I'm not sure how it would be in the dry season. Maybe someone else can chime in on that. It's a great place to see water birds, and we've seen monkeys, sloths, and caimans there as well.

Cano Negro and Arenal are crap in the dry season.Windy and dusty. Monteverde is missing only one thing. A guy in a mouse suit !
Do Rio Celeste instead. Tenorio nat'l park is like Monteverde was 25 years ago.The birds and animals are there. Get up at 4 AM and head out the door by 445 or so. You'll see all the birds you ever could imagine.
Yes. The OSA is the most incredible place on earth.You MUST go there. Stay at La Paloma lodge. Mike will hook you up with whatever you'd like to do.

Thanks for the continuing input. We may consider changing the timing of the trip so as to avoid the dry season, but are looking at February to celebrate my husband's milestone birthday.

I'll continue reading, selecting, narrowing and hopefully have a tentative itinerary soon.

Yeah, three weeks in Costa Rica is just the right amount of time. Here are some advices based on our experiences (same age and interests):
1. rent a car! A small 4x4 is needed like Daihatsu Terios or Toyota RAV4
2. San Jose - Cerro de la Muerte for quetzales. Between KM 70 and KM80 of the Panamerican Hwy 2 (Interamericana Sur) there are severals lodges well known for excellent birdwatching.
3. Next to Osa peninsula. Basically 2 options: Puerto Jimenez if you are into selfguided hiking around Cabo Matapalo area or a day hike into Corcovado NP. Or Drake Bay for easy access to La Sirena Ranger station, the heart of Corcovado NP, and a place if you want to overnight in this amazing NP. Always with a guide!
4. Back north up the Costanera Sur, a coastal road on the Pacific side. Very good birdwatching place with excellent guides is Hacienda Baru. Or stop at Carara NP.
5. Then north again and up to Monteverde. Despite some comments above it is a place not to be missed. With a good private guide you will see lot of birds and few of tourists. Santa Elena Reserve or San Luis waterfall are nice to intense hikes.
6. On the Caribbean side best wildlife and birdwatching is in the Sarapiqui area. La Selva, Tirimbina and Rio Sarapiqui.
7. Tortuguero is also a must stop, very different place with its canals.
8. End your journey in Puerto Viejo with some days for relaxing on the beach and some days for exploring the Cahuita NP (easy selfguiding) and Gandoca Manzanillo NP (more demanding, with a guide).

Really, don't worry so much about the wet or dry seasons. I've been to Cano Negro in both, and have seen an equal amount of wildlife. If anything, our dry-season trip was more enjoyable because it didn't pour the entire time. Sarapiqui and Tortuguero can be wet any time of the year, harder to predict.

Re:renting a car, dh and I are in the camp that prefers being driven, for several reasons - our propensity to get lost, our lack of Spanish, and the (to us) scary driving.

#2 on xelas's list is the cloud forest (Savagre Lodge) that I posted about earlier in this thread.. Please forgive my typos!

Oh, and that's 3 visits to CR, not 93, lol - (yet)!

You might also want to check out Rancho Naturalista http://www.ranchonaturalista.net/ for excellent mid-altitude birding outside of Turrialba and Bosque de Paz for easy access (on the way to Arenal) cloud forest environment and loads of hummingbirds. http://www.bosquedepaz.com/

I usually go for three weeks each trip, great amount of time to cover some distance in a relaxed manner.

Cattail - saw that 93 trips and thought how lucky!!!

Check out Shelter from the Storm www.shelterfromthestormvillas.com if you choose to stay in the Dominical / Uvita area which is not as developed as the rest of Costa Rica ( not including the Osa, of course!!). The Ballena Coast as this is called has lots of activities and beautiful beaches. It is close to Hacienda Baru where there is great birding available.

How about Durika?

www.durika.org

...or if you're feeling particularly adventurous, Highland Heritage.

http://frontiercostarica.com/FrontierCostaRica/index.htm

Both are situated in the cloudforest of the Talamanca Mountains right next to La Amistad International Park. Your point of access would be from Buenos Aires, just off the Interamericana.

Good guides at Hacienda Baru (ask for Pedro especially if you do the rainforest trek as you need someone with good ears and eyes), Savegre (any Chacon but you will love Marino), also the young guide Ersel at Arenas del Mar.

Arenal Observatory Lodge is a great spot for hiking and birdwatching, too.

We did the Cano Negro tour in the dry season (February) and thought it was great. Saw lots of birds, lizzards, monkeys...just go. You will love it.