First the ‘big’ picture: You’ll be traveling West from the Airport, through Putarenas where ‘the cruise ships’ dock, then turning West at the famous Tres Hermanas restaurant, across the Peace bridge to get to the Nicoya Peninsula (Guanacaste Province), down to Nicoya, then South almost to Samara, then the last section NW to Prados del Sol.
Now the details.
You will start by taking highway number 1 West (the specifics depend on who you rent your car from - ask where you rent your car, it will be easy to find.)
You then turn South (take the loop to your Right) onto "Radio El Coyol", see the close up of the intersection below:
Note: If you want a simpler path that takes about 25 minutes longer on average, you can stay on the number 1 and not make this turn. If so, just stay on the number 1 and skip down in this page to where the faster route turns back onto the number 1.
The path below is slightly more complicated - but it really isn't hard, and it saves almost half an hour.
If you have a GPS though, check and see with current traffic what the time difference is, use that info to make your choice.
You head down and turn West by taking the second road in the round-a-bout. (See the close up image below)
Stay on the number 27 all the way to the ocean. I am NOT showing maps of the 27. Just stay on it until you get here:
The number 27 turns into the number 23.
Stay on the number 23 going through Puntarena (don't take the turn to Puntarena)
A few minutes later, the number 23 will do a 270 degree turn onto the number 1 heading NW.
Continue mostly North and West until you get to 3 Hermanas (3 Sisters) with a large statue of a Sabo (A cow like animal.)
Now you will turn West (Left) onto highway number 18. The image above will be on your left before you turn and on your right after you turn onto Highway number 18.
Stay heading West on Highway number 18, you will go across the Peace Bridge. (The image below is looking back after you cross.)
A good place to take a break, but there is a small charge to use the washroom. You'll want to come back here and take the 'Captain's Dream' boat trip to see the Crocodiles and many species of birds. But … this page is helping you get to Prados del Sol so, continue on the number 18 until you get to the number 21. Turn West (Right) onto Highway number 21.
Continue to Nicoya. You can follow the blue line below or you can continue to turn at the KFC which will give you access to the town of Nicoya including gas stations.
The map above ends with you turning towards Nicoya at the KFC, then going through Nicoya, or bypassing most of Nicoya. Either way you end up heading South towards Samara. See the page for details turning into Nicoya and from there to Prados del Sol.