Move from tight basalt tunnels to a steaming mountain river in one energetic day out of Reykjavik. This guided trip pairs hands-on caving with a geothermal soak—expect crawling, scrambling, and a well-earned hot dip.
More ways to explore the area's outdoor wonders
The morning light over the Reykjanes hills feels unapologetic: steam seams rise from the earth and a breeze carries a mineral tang that sticks to your jacket. You set out from Reykjavik in a small van with a few other travelers, the city shrinking behind you and a ragged lava landscape growing bolder. Hikers become spelunkers and then bathers over the course of one compact day — you climb, crawl, and then sink into a thermal stream that seems to sigh with relief beneath the mountain.
Difficulty
challenging
Duration
6–7 hours
Fitness Level
Should be in good aerobic condition and comfortable with sustained hiking, scrambling, and crawling.
Wildlife
History
The Reykjanes region records Iceland’s volcanic rhythms: lava tubes are relics of historic eruptions and geothermal use stretches back to early settlements who relied on heat for cooking and bathing.
Conservation
Stick to designated trails and avoid walking on delicate lava moss; geothermal areas are fragile and repairs can take decades, so minimize impact and pack out all waste.
Reserve your spot on the Hot and cold G spots challenge today and enjoy a trusted, highly rated experience designed to help you make the most of your adventure.
Bring a full clothing change
Caving is wet and dirty; pack a waterproof dry bag and a warm set of clothes to change into after the hot stream.
Wear stout, grippy boots
Choose ankle-supporting hiking boots with good tread for wet rock and mud in caves and on valley trails.
Protect electronics
Use a small waterproof case or zip-top bag for phones and cameras, and bring spare batteries—headlamp batteries drain fast in cold.
Pace yourself on the crawls
Guides will set progression; conserve energy for the later, tighter sections and the hike out to the hot stream.
Waterproof hiking boots
Support and traction on wet basalt and uneven cave floors.
Layered synthetic clothing
Fast-drying base and insulating mid-layer for cold caves and variable weather.
Waterproof pack or dry bag
Keeps spare clothes and electronics dry during caving and river time.
Reusable water bottle and high-energy snacks
Hydration and calories for a long day of exertion.