Day 4

Breakfast at the hotel. Day to enjoy Arenal area - you can go to Arenal National Park, hike to La Fortuna Waterfall, see the volcano up close or drive to Arenal Lake, among other things. You can do many of the activities independently (using local taxies and walking), or with a local tour company (you can get more information and book the tours through the Tour Desk at the hotel).
Overnight stay at Hotel Arenal Paraiso.