We have been to Costa Rica twice and loved it both times. Both times rented a car and did B&B stops everywhere. The only resort type place we stayed was Ocotal Beach Resort on the Pacific side West of Liberia which was very nice, but not really our cup of tea. We prefer more interesting and off the beaten track a bit. Ocotal is very nice, the room we were in was more like a small house than a hotel room. The dining area for the hotel is built on a bluff overlooking the ocean, very romantic at night. They do dive charters and fishing charters the weather is almost universally hot and dry. You will find that it is pretty isolated however and at the edge of cattle country - hot, dry grasslands - probably the least scenic part of the country.
I am not sure I would go to Costa Rica to stay in a single resort. The attraction to me was the country itself. It has something like 8 climactic zones ranging from dry desert, temperate rainforest, tropical rainforest, cooler mountian regions - basically you can find everything you want but snow. Means the life is incredably varied.
Did not do much diving, one trip off Bat Island from the Ocotel resort which was very good - was in the middle of a ?school? of Manta's. The other trip was just off Manuel Antonio. A bit of a disaster and a very short dive. Had all the elements of a good dive, but I managed to get myself in trouble and had to cut the dive short and then couldn't dive again for a week or so.
Never have made it to the Caribbean side, got part way down the mountians and decided we didn't like what we were seeing so went back to the Pacific side. Subsequently have heard good things about some resorts down on the beach on that side of the country.
A great place for an adventure holiday. We have stayed on a coffee plantation, a birder's B&B, a tree house on the beach, a B&B with three Great Danes and an orchid garden, a small hotel with jungle theme murals on every wall and monkeys in the back yard. By and large we have found interesting places to stay and lots to see and do both times we were there. Would go back to the San Juan area, Arenal area, Nicoya Peninsula and Quepos. Would give a pass to Liberia and Punterenas.
Both trips diving was just something I squeezed in among a bunch of other things - so was not the focus of the trip. I don't recall any good snorkling anywhere we went. Nice beaches, but no snorkling. However was not looking, was more focused on other things.
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