Iceland went from about half a million annual visitors to over two million in a decade, and it shows in exactly the places you would expect: the Golden Circle, the south coast waterfalls, and the Blue Lagoon. Everywhere else on the island still has more sheep than people.
A week is not enough for the full Ring Road unless the point is the driving. It is comfortably enough for one region done at a reasonable pace.
The season decision, which is really two trips
Summer, June to August. Near-24-hour daylight, all roads open including the interior F-roads, the highlands accessible, puffins, whales, and every hostel booked. No northern lights — the sky never gets dark enough.
Winter, November to March. Northern lights, ice caves, snow, four to six hours of daylight, dramatically lower prices, and a genuine risk of being weathered in. The Ring Road is often passable and sometimes not; the highlands are closed entirely.
Shoulder, April–May and September–October. The best compromise: enough darkness for aurora by late September, most roads open, and half the crowd.
You cannot have midnight sun and northern lights on the same trip. That is the first thing to settle.
Option one: the south and east
The most popular route, and the one with the highest density of things.
Reykjavík, 1 night. Small, and the Hallgrímskirkja tower is the best view. Skip the Blue Lagoon — it is a industrial-runoff spa near the airport with a booking system; Sky Lagoon is better and the local municipal pools, which every Icelandic town has, are where Icelanders actually go and cost a few pounds.
The Golden Circle, 1 day. Þingvellir, where the parliament met from 930 and where the tectonic plates are visibly separating; Geysir; Gullfoss. It is genuinely good and it is very busy — go at eight in the morning or at five in the afternoon.
The south coast, 2 days. Seljalandsfoss and Skógafoss; the black beach at Reynisfjara, where the sneaker waves are lethal and have killed visitors — stay well back from the water; Fjaðrárgljúfur canyon.
Skaftafell and Jökulsárlón, 2 days. Glacier walks on Vatnajökull, Europe’s largest ice cap, and the glacier lagoon with icebergs floating out to Diamond Beach. This is the best part of the south and most day tours from Reykjavík turn round before it.
The eastfjords, 1 day, if you have the time — empty, and where the reindeer are.
Option two: the north and the Westfjords
For a second visit, or for anyone who would rather have space than sights.
Akureyri, the northern capital, flyable from Reykjavík.
Lake Mývatn — pseudocraters, lava fields, the Dimmuborgir formations, and a geothermal bath that is the north’s much quieter answer to the Blue Lagoon.
Dettifoss, the most powerful waterfall in Europe by volume.
Húsavík for whale watching, which is the best in the country.
The Westfjords, a peninsula in the far north-west, are the emptiest part of Iceland: Dynjandi waterfall, Rauðasandur’s red sand beach, the Látrabjarg bird cliffs with puffins at arm’s length, and hours of gravel road between them. Summer only, realistically.
Driving, which is the main hazard
Wind is the thing that damages hire cars, and door damage from wind is specifically excluded from most insurance. Hold the door when you open it. This is not a joke; it is the most common claim in the country.
F-roads require a 4x4 by law, are summer-only, and involve unbridged river crossings which are excluded from every standard insurance policy.
Single-lane bridges and blind summits are everywhere and are marked. The car on the bridge first has priority.
Weather closes roads at short notice. Check road.is and vedur.is every morning without exception. Icelanders do.
Do not drive off-road. It is illegal, the fines are severe, and the moss takes decades to recover.
Northern lights, honestly
They require: darkness (September to April), a clear sky, and geomagnetic activity. All three coincide less often than people expect, and a week in winter gives you a reasonable but not guaranteed chance.
Get away from town lights, check the aurora forecast on vedur.is, and be prepared to be outside at one in the morning in a wind that makes -5°C feel considerably worse.
Costs
Iceland is expensive — comparable to Norway and Switzerland. Alcohol is punitive.
What brings it down: supermarket food from Bónus or Krónan rather than restaurants; guesthouses and campsites rather than hotels; the municipal swimming pools instead of the branded lagoons; and travelling outside July and August.
Petrol is a substantial cost on the Ring Road.
What a week does not fit
The Highlands — Landmannalaugar, Þórsmörk, the Laugavegur trek — which are summer-only, need a 4x4 or a bus service that runs for about ten weeks a year, and are the best landscape in the country.
The full Ring Road at a pace that is not a driving marathon. It needs ten to fourteen days.
The Westfjords and the north together.
Costs, in brief
Iceland sits with Norway and Switzerland. The levers are supermarket food from Bónus or Krónan, guesthouses and campsites rather than hotels, the municipal pools instead of the branded lagoons, and travelling outside July and August. Petrol on the Ring Road is a substantial line of its own.