Stayed 8 days with Hotel Kokoro and it was absolutely wonderful. Saw a diversity of guests: young & elderly couples, families with young kids, and international guests.
The staff was friendly and kind. Everyone we interacted with spoke multiple languages including English. Every day there was maintenance of the property, ensuring cleanliness of the pools, tidiness of the walkways, and attention to the beautiful landscaping.
This hotel was really charming because the lodging is nestled into the natural environment of the surrounding rainforest/jungle. There is a clear and epic view of Mount Arenal and it's possible to book a room with a patio facing it.
Our stay included breakfast every morning. Each meal for the duration of our stay included some variation of eggs, beans & rice, plantains, and cooked vegetables. Pancakes, bread, butter, juice, and water were also served every morning with fresh fruit such as pineapple, watermelon, and papaya. Overall it was very satisfying (buffet style).
The last week of January leading into the first week of February, there were mild rainy days. Most of the rain fell at night, but the temps stayed above 75 degrees in the daytime. Very pleasant. The sunny days were perfect for poolside and walking the jungle trail on the property.
As for the hot springs... they appear an unusual color from the other springs you may encounter in La Fortuna, however they were very pleasant to use and didn't seem to have anything wrong with them.