South Aegean, Greece
Walk across a dormant hydrothermal crater. Boiling mud, sulfur crystals, and 100°C fumaroles fill the 300-meter-wide Stefanos Crater.
4.5 from 549 traveller reviews on Viator
Tickets & tours
Organized excursions and boat tickets from Kos.
Most bookedEnjoy this one hour cruise to the Dodecanese island of Nisyros and enter the crater of the volcano where you can feel lava rumbling beneath your feet. One of the most...
Best valueWe sail to Nisyros from Kardamena port on our boat. Nisyros is one of the smallest islands of the Dodecanese, and the boat trip from the island of Kos is only about 1...
Top ratedYour first stop is Agios Antonios, where you can swim in crystal-clear waters and enjoy a delicious BBQ on board. Relax, sunbathe, and admire the stunning scenery before...
Explore
Key locations around the caldera.
3 spotsStefanos Crater FloorWalk across boiling mud and sulfurous steam at Nisyros' core.Explore Photo: tour listing on Viator
3 spotsMandraki VillageThe port capital of Nisyros with whitewashed houses and narrow alleys.Explore Photo: tour listing on Viator
3 spotsNikia VillageHillside village on the caldera rim with views of the craters.Explore Photo: tour listing on Viator
The Stefanos Crater is 27 meters deep and sits inside a 4-kilometer-wide caldera.
Formed by massive eruptions 25,000 and 15,000 years ago.
Plan your visit
Expect 7 to 8 hours for a full-day trip from Kos. You need 30 to 45 minutes inside the crater.
Arrive at the crater between 9:00 AM and 11:00 AM. This avoids the intense midday heat.
Ferries run from Kardamena port in Kos. The crossing takes 45 to 60 minutes.
Boat tickets cost €20 to €35. Bring €5 cash for the crater entry fee.
Nisyros is a dormant but active hydrothermal volcano in the Dodecanese archipelago. Most visitors arrive on a day trip from Kos to see the Stefanos Crater Floor. The island is a UNESCO Global Geopark due to its preserved volcanic landscape.
The main draw is the Stefanos Crater. You can walk directly on the crater floor among hissing fumaroles and bright yellow sulfur crystals. The ground is hot, and closed-toe shoes are mandatory. See Packing & Dress Code for packing advice.
Beyond the crater, the island features traditional settlements. Mandraki Village offers narrow alleys and a clifftop monastery. High on the caldera rim, Nikia Village provides bird's-eye views over the entire 4-kilometer-wide volcanic basin.
We use actual travel times and prices.
We highlight when the €5 crater fee is extra.
We explain the bus ride from the port to the crater.
From Viator
549 reviews of the full-day nisyros tour on Viator
A great experience from start to finish, can be a bit of a long day but thoroughly enjoyable, good comfortable shoes required
Really enjoyable day out. The volcano and the Monastery in the 'Capital' of the island were both lovely to visit. Nice short boat trip out of 50 minutes. Guide was friendly and well organised.
Fantastic day out, "Little Santorini" far exceeded my expectations. What a stunning place. Our guide for the day, Manoli, was so knowledgeable and entertaining. Had gyros at a beach side restaurant, lovely food and view. Not wanting to put pictures or too much info as it would spoil the "ahhh" moment. Would totally recommend.
We had a amazing time here it was so lovely. And the Young girl anastasia was amazing with the entertainment getting us all to join in with everything taking part in all the activities she always had a smile on her face the job is definitely for her she is a natural ❤️ 😊 x
No frills trip. Boat journey, bus to crater and return trip. A German tourist guide who was nothing to do with the paid for journey gave us some brief commentary in English which was a bonus. Well worth the trip with no problems encountered.
Awesome experience day was well planned. Boat trip was nice cruse then got to niyros into coach was took to the village first., whilst other trips went to the volcano. So after 40 mins we went to the volcano which was epic.
Great day out for a family with 3 stops at amazing locations, not often you get to see a volcano and snorkel on the same day!
Beautiful experience. Unforgettable day. Well organized excursion so you can enjoy every site. Nice pirate ship.
A totally different tour from the typical islands tours, where you mostly swim in crystal clear waters. You get to visit a small village and taste their amazing products. The visit to the volcano was amazing, and Martha gave us many information and was very clear on the meeting time and meeting point!
Travel tips
Trip Cost GuideBreak down the costs of tours vs independent ferry trips to Nisyros.Read 
Travel from KosCompare ferries and organized tours from Kos to Nisyros.Read 
Packing & Dress CodeFind out exactly what to wear and pack for the hot Stefanos crater.Read 
Visiting With KidsSafety rules, heat management, and tips for taking children to Nisyros.Read Best Time to VisitFind out the exact times to visit the crater to beat the extreme afternoon heat.Read Guided vs. IndependentCompare organized tours with DIY travel for your Nisyros volcano trip.Read Yes, it is safe if you follow the rules. The volcano is dormant. You must stay on marked paths and never touch the fumaroles or boiling mud. The steam reaches 100°C (212°F) and causes severe burns.
Yes, visitors can walk directly across the bubbling crater floor. The Stefanos crater is 300 meters wide. You must wear closed-toe shoes to enter.
The boat trip from Kardamena port on Kos to Mandraki port on Nisyros takes approximately 45 to 60 minutes.
The entry fee is €5 per adult. Young children often enter for free. You pay this in cash at the ticket booth at the crater entrance.
No, but it is the most convenient option. You can book simple
and rent a car or take a local bus upon arrival. Organized tours include the bus transfer from the port to the crater.Closed-toe shoes are mandatory. Sandals are strictly prohibited due to the hot ground. Wear a sun hat, sunglasses, and strong sunscreen. Read more in Packing & Dress Code.
Check tour availability from Kos and book your spot.
