Golden Circle Add-Ons Compared: Lagoon, Snorkel or Crater
Blue Lagoon, Secret Lagoon, Silfra snorkeling, Langjökull snowmobiling and Kerið crater compared by cost, hours added and season, with real current prices.
By Björn Einarsson, Iceland Golden Circle tour guide and local specialist
The parking lot at Gullfoss is where the arguments happen. I hear them every week: a couple leaning on the railing, spray drifting sideways, one of them holding a phone with four tabs open. Lagoon or glacier. Snorkel or crater. They have one day, the route takes most of it, and every add-on promises to be the thing they will still talk about in ten years.
Some of those promises hold up. Some cost you 33,990 ISK to find out they do not. I have watched thousands of travelers come back to the bus glowing, and a smaller number come back shivering and quiet. This is my honest ranking of the add-ons people actually bolt onto the classic route, with real prices and the trade-offs nobody prints on the brochure.
Which add-on is worth your extra hours: lagoon, snowmobile, snorkel or crater?
For most first-timers the Blue Lagoon is the safest add-on: a two-hour soak that works in any weather and ends the day instead of crowding it. Kerið is the cheapest yes at 700 ISK. Silfra and the Langjökull snowmobile are unforgettable but half-day commitments that reshape your whole schedule.
Here is the thing the tabs-open couple usually misses: the question is not which add-on is best. It is which kind of tired you want to be at 7 pm. A lagoon rewards the tired body. A glacier rewards the restless one. The crater asks almost nothing of you, thirty minutes and a few hundred krónur, which is exactly why I keep recommending it.
| Add-on | Entry cost from | What it asks of your day | How you book it |
|---|---|---|---|
| Kerið crater | 700 ISK | A 30-minute stop right on Route 35 | Pay at the gate, or included on some tours |
| Secret Lagoon | 4,500 ISK | A relaxed soak stop near Flúðir | Book direct, short detour off the route |
| Blue Lagoon | $95 (USD) | A 2-hour ending, pre-booking required | Timed ticket, or included in a combo tour |
| Silfra snorkeling | 19,990 ISK | A meet-on-location half-day at Þingvellir | Separate operator, fixed time slots |
| Langjökull snowmobile | 33,990 ISK | A meet-on-location half-day above Gullfoss | Separate operator, glacier transfer included |
Read that middle column twice. The two water-and-ice adventures are not stops, they are anchors. Everything else in your day gets planned around them. The two lagoons and the crater are the opposite: they bend around your day. If you booked a standard 6.5 to 11 hour tour, only the bendable ones fit without surgery, and the combo tours that pre-package an anchor have already done the surgery for you.
What does each add-on cost?
Current entry prices run from 700 ISK for Kerið crater to around 33,990 ISK for a Langjökull snowmobile seat. The Secret Lagoon charges 4,500 ISK for adults, Silfra snorkeling starts at 19,990 ISK meet-on-location, and Blue Lagoon admission starts from $95 with pre-booking required.
Prices in Iceland move, but the ladder between them stays remarkably stable: each rung roughly triples the one below it. That ladder is the most useful budgeting tool I can give you, and it is worth holding next to the base cost of the day itself, which I broke down in what a full day on the route actually costs.
| Cost item | Price | The fine print |
|---|---|---|
| Kerið crater service fee | 700 ISK per person | Charged at the gate, card accepted |
| Secret Lagoon adult admission | 4,500 ISK | Towel rental extra, book ahead in summer |
| Blue Lagoon Comfort admission | from $95 (USD) | Timed entry, pre-booking required, price rises with demand |
| Silfra snorkeling | from 19,990 ISK | Meet-on-location rate, dry suit included |
| Langjökull snowmobile | from 33,990 ISK | Meet-on-location rate, gear and glacier transfer included |
Two warnings from the road. First, the Blue Lagoon prices in dollars and sells timed slots, so the $95 floor is real but the slot you want on a Saturday evening usually costs more. Second, "meet-on-location" is doing quiet work in those bottom rows: it means you drive yourself to Þingvellir or to the Gullfoss area base camp. Add Reykjavík pickup and the price climbs fast.
Is the Blue Lagoon ending worth it?
Yes, if you treat it as the ending rather than a detour. After eight hours of wind, waterfalls and gravel paths, two hours in 38-degree-feeling milky water is the single most reliable payoff in Icelandic tourism. The catch: pre-booking is mandatory and same-day slots vanish in summer.
I am biased here, and I will tell you why. The failure mode of a long day on the route is not boredom, it is accumulation: cold fingers at Gullfoss, a wet hood at Öxarárfoss, three hundred photos and no moment where your shoulders actually drop. The lagoon is where they drop. I have seen the quietest bus of the day roll away from that parking lot, and it is a good quiet.
The logistics are the real question, because the lagoon sits near Grindavík, well off the loop. Driving yourself means finishing the circle, then adding a separate leg, then matching your arrival to a timed ticket you bought days ago. This is precisely the surgery a combo tour has already done. The 11-hour small-group day I point people toward runs the full route, adds Kerið, and lands you at the lagoon with admission already in the price. If that shape fits your day, book the Small-Group Blue Lagoon combo and check live availability and prices on Viator for your date, since the live price only shows on the listing.
| Stop on the 11-hour combo day | Time you get |
|---|---|
| Þingvellir National Park | 45 min |
| Geysir and Strokkur | 1 h 20 min |
| Gullfoss | 40 min |
| Kerið crater (admission included) | 30 min |
| Blue Lagoon (admission included) | 2 h |
That last row is the whole argument. Two unhurried hours, towel in hand, nothing left to catch except the drive home.
Is the Secret Lagoon a better fit than the Blue Lagoon?
Sometimes. The Secret Lagoon at Flúðir costs 4,500 ISK, sits minutes from the route, and feels like a village pool from 1891 because it is one. Choose it for budget, geography and a local mood. Choose the Blue Lagoon for the spa polish and the grand finale feeling.
Travelers ask me this one on the bus more than any other, usually framed as "is the Blue Lagoon a tourist trap?" It is not, but it is a production. Swim-up bar, silica masks, architecture that belongs in a magazine. The Secret Lagoon is the opposite instinct: a hot pool in a field, steam drifting over the grass, a little geysir burping beside the deck every few minutes.
Geography decides this for many people. Flúðir sits just off the route near Friðheimar, so the Secret Lagoon slots into the middle of a self-driven day without adding a leg, and pairs naturally with a tomato-soup lunch, something I covered properly in where to actually eat on the route. The Blue Lagoon demands the end-of-day commitment. On a January trip the calculus shifts again, because a dark 4 pm soak under falling snow flatters both pools; the winter version of this day has its own rules, which I wrote up in the route in winter.
| Secret Lagoon | Blue Lagoon | |
|---|---|---|
| Price | 4,500 ISK | from $95 (USD) |
| Location | Flúðir, minutes off the route | Near Grindavík, separate leg after the loop |
| Booking | Book ahead, simpler in shoulder season | Timed pre-booking, mandatory |
| Mood | Village pool, grass and steam | Designed spa, silica masks, swim-up bar |
| Fits a tour? | Rarely included | Included in the 11 h combo with Kerið |
What are Silfra snorkeling and Langjökull snowmobiling really like?
Extraordinary, and demanding. Silfra means floating between the continental plates in water that holds 2 to 4°C all year, sealed in a dry suit, from 19,990 ISK. The snowmobile is a roaring hour on Langjökull's white dome from about 33,990 ISK. Both are half-day anchors, not stops.
Silfra first, because it happens inside Þingvellir, a place your tour already visits. The visibility is the thing no photo prepares you for: the fissure water is glacial melt filtered through lava for decades, and you can read the gravel thirty meters down. Your face goes numb in the first minute. Then the numbness fades behind the view and forty-some minutes later you are drinking hot chocolate in a parking lot, changed slightly. The dry suit keeps your body dry and warm enough; your lips just pay the entry fee.
The snowmobile is a different animal. You meet above Gullfoss, ride a monster truck onto the ice cap, then drive your own machine across a landscape with no fixed features at all, white to every horizon. It is loud, fast and weather-ruled: the glacier cancels days the lowlands consider fine. Neither activity coexists with a standard coach tour schedule, and neither should be attempted as a squeezed-in extra. Give them the half day they demand or skip them for this trip.
Is Kerið crater worth the 700 ISK?
Easily. Kerið charges a 700 ISK service fee, roughly the price of half a coffee in Reykjavík, for a 3,000-year-old volcanic crater with rust-red slopes around an opaque aquamarine lake. It takes 30 minutes, sits right on Route 35, and photographs better than things costing fifty times more.
I have stood on that rim in July when the slopes glow like brick and in February when snow picks out every ridge above the frozen lake, and I have never once heard a traveler complain about the fee on the walk back. The rim loop is an easy stroll; the steps down to the lake add ten minutes and are worth it when the path is dry.
The honest criticism is that Kerið is a snack, not a meal. If your day is already bursting, it is the first thing to cut, and nobody's trip was ruined by skipping it. But that logic cuts the other way too: because it costs almost nothing in money or minutes, it is the highest-ratio add-on on this list. The two tours in our lineup that include it fold the fee into the ticket, so on those days the question answers itself. On a self-drive, keep a card handy at the gate and do not overthink 700 ISK.
Bring a windproof layer even in summer. The rim catches every gust crossing the lowlands, and the difference between a miserable circuit and a great one up there is one zipper.
Quick questions travelers ask about add-ons
Can I do two add-ons in one day?
Pair one anchor with one snack. Silfra in the morning plus Kerið in the afternoon works on a self-drive. The Blue Lagoon plus Kerið works because the combo tour builds exactly that. Two anchors, like Silfra plus a snowmobile, means dropping route stops and racing daylight.
Do I need to book add-ons before I arrive in Iceland?
The Blue Lagoon, yes, days ahead in summer since timed slots sell out. Silfra and snowmobile slots also fill, book once your dates are firm. The Secret Lagoon is more forgiving outside peak weeks, and Kerið never needs booking, you simply pay at the gate.
Which add-on is best in winter?
The lagoons. Hot water under falling snow is the version postcards are made of, and both operate through the dark months. Silfra runs year-round too, the water never leaves its 2 to 4°C band. The snowmobile is the most weather-exposed choice, so keep a flexible plan around it.