The crater
An acid lake.
Peter Andersen — CC BY 2.5 · MongeNajera — CC BY-SA 3.0 · Scott Robinson from Rockville, MD, USA — CC BY 2.0 · MongeNajera — CC BY-SA 3.0
An active volcano about 2,697 metres high whose summit opens into a wide, deep grey crater, sometimes holding an acid lake of milky turquoise that steams amid walls stained by sulphur. It is one of Costa Rica's most visited volcanoes and has erupted more than forty times since 1828. From the car park visitors walk a short paved path to the lookout on the crater rim, where they may stay only a set few minutes because of volcanic gases. The view is awesome on a clear morning, but clouds usually fill the crater after mid-morning, hiding it completely. The park closed for many months after a strong eruption in 2017, and again from March to July 2025 as activity rose, reopening with extra safety measures. The highlands around it are strawberry, coffee and dairy farms with country restaurants. Visits need a compulsory advance booking for a set time slot. The summit is cold and damp, so bring a jacket. Volcano parks sometimes close when activity rises, so check their status before going, and go early before the clouds gather.
An acid lake.
A few set minutes.
Strawberries and coffee.
Poás Volcano National Park, about an hour and a half north-west of San José
Yes, an advance booking for a set time slot on the SINAC site is compulsory, and morning slots sell out fast in high season.