Surviving “Montezuma’s Revenge” and Hiking Cerro Chato from the Arenal Observatory Lodge


by Mr and Mrs Adventure | May 29th, 2014
The sun was shining, horses were grazing in the lush, green grass and Arenal Volcano was clearly visible against blue Costa Rican sky. Perfect day right? From the photo above you would never be able to tell that just a few hours earlier I was curled into fetal position, completely immobilized by some terribly evil stomach virus, Drew had it too, but luckily he was able to overpower it a bit better than I. Here’s our little cabin in La Fortuna that I thought I would never leave.
Unable to walk, Drew carried me to the nearest “Farmacia” and luckily the doctor knew exactly what I needed – I still don’t know what he gave me, and quite frankly I don’t care, I’m just grateful that it worked and I lived to tell the tale. A few miraculous hours later we were back on track and on our way to the beautiful Arenal Observatory Lodge to hike Cerro Chato – we had been looking forward to this the entire trip and nothing was going to hold us back.
Entrance to Arenal Observatory Lodge
Cerro Chato is an extinct volcano that has been inactive for some 3,500 years and rests on the southeast side of the Arenal Volcano reaching an elevation of 3,740 feet.  There is now an emerald pool (photo below) that fills Chato’s hollowed crater where the lava once boiled, and while you are allowed to go swimming in it, there are certain minerals present in the water that make swimming inadvisable.
We had originally planned to start the 6ish mile hike at 8am and finish in time to enjoy lunch at the Observatory restaurant, but due to unforeseen circumstances, we didn’t get to the lodge until about 1:30pm. The friendly people at the reservations desk let us know that the absolute latest one should start the hike is at 2pm because it takes 4 hours round trip and the sun goes down by 6pm in Costa Rica. So, they gave us a map and off we went!
Cerro Chato from Arenal Observatory Lodge
The trail started off on the lodge’s property – we crossed over an awesome suspended bridge and passed by some of the most incredible tropical flowers we had ever seen:
Cerro Chato Hiking tour
10 minutes later we made it off the beaten path and found ourselves on a long and winding road with Cerro Chato staring right at us beyond the clouds.
The different colored trails, labeled on the map featured earlier, were clearly marked with colored blocks the entire way. Below you can see the blue trail marker on the beautiful Rainbow Eucalyptus, known to have the most beautiful bark in the world. These markers made it easy to stay on track, despite the many unique distractions:
Arenal Observatory Lodge
Not many hikers passed us at this time of day, maybe 3 sets of people the entire time. It’s definitely more popular as a morning adventure, but for us it was nice to feel like we had the place all to ourselves… all to ourselves plus these two odd and unforgettable birds! Known as the Great Curassow, it is apparently extremely rare to encounter one, let alone two!
After admiring our new friends as long as they would allow us, we hiked a few more meters until we found ourselves at the base of Arenal’s older brother, Cerro Chato. This is definitely not a beginner’s hike – they even have a sign at the trailhead to warn people one last time – though Drew and I both believe that as long as you go at your own pace and have enough water, anyone can do it.
Cerro Chato hiking tour
Roots and mud were definitely the defining elements of this unforgettable hike. After nearly an hour of huffing and puffing, we found ourselves at the glittering emerald green mouth of Cerro Chato:
After enjoying the view and a much needed rest, Drew decided that it was time to hike down to the lagoon. After some hesitation on my end, he finally convinced me and as usual, I was definitely glad he did. We were basically crawling up and down muddy foot wedges made by the many whom had gone before us. Because the top of Cerro Chato rests in a cloud forest, nothing ever really dries out – it was quite the experience.
15 minutes of mud crawling later, we made it to the emerald lagoon and boy was it worth it. With not a soul around, we took in the wild sounds of the rain forest and watched as the clouds rushed over us and the glimmering green waters.
Mr and Mrs Adventure
Up and at it again, we made our way back down to the Observatory Lodge in about an hour, just in time to be guided back by the setting sun and the glowing neon lights of the fireflies.
Completely satisfied with our journey, grateful for our health and extremely hungry from the trek, we took a seat at the Observatory restaurant to enjoy a beautiful meal, complete with deliciously refreshing mango and blackberry juice.
Mr and Mrs Adventure
It’s hard to believe that Montezuma’s Revenge and our epic hike up Cerro Chato happened on the same day! All we can say is that where there’s a will (and a pharmacy!) there’s a way :)

Things to know:

  • If you are only going to be in Costa Rica for a week or so, be safe and just buy your water. We were told especially NOT to drink the water in the beach towns… Jaco did it for us.
  • You do not need a 4-wheel drive vehicle to get to the Lodge
  • You can start the hike from Arenal Observatory Lodge as early as 6am
  • Latest to start the hike is 2pm
  • Entrance fee to AOL is $8 per person
  • Give yourself at least 4 hours to do the hike no matter what your fitness level, especially if you decide to add the side hike to  the lagoon (which you totally should)
  • Bring a lot of water, there is no where to refill along the way.
  • Stop at the Observatory restaurant for lunch, dinner or a sunset drink – this spot offers one of the best and closest views of Arenal
  • Be sure to check out our posts from earlier on our trip! There was Exploring Manuel Antonio, Whitewater Rafting on the Rio Savegre, Celebrating my Birthday with Kayak Jaco, and Getting Engaged on Isla Tortuga with Calypso Cruises !
  • And check out our awesome Costa Rica blogging friends at Pura Vida eh? who got engaged at Cerro Chato!