The drive from Reykjavík to Vík í Mýrdal covers about 190 km and takes just under three hours without stops, but nobody drives it without stops. Seljalandsfoss, roughly 125 km southeast of the city, drops 60 meters over a mossy overhang, and a paved path lets you walk behind the curtain of water for a soaked, slightly ridiculous five minutes; bring a dry bag for your phone.

Twenty minutes further, Skógafoss thunders down a 25-meter-wide cliff face, and the 527-step staircase beside it climbs to a viewpoint over the start of the Fimmvörðuháls hiking trail. By late afternoon we reached Reynisfjara, the black sand beach beneath the basalt sea stacks of Reynisdrangar, where the surf is genuinely dangerous and the warning signs are not decorative.

We overnighted at Hotel Rangá, about 15 km outside Hella, whose lobby log fire and lava-field views made it worth the small detour off Route 1. Rooms in September run roughly USD 350-450 a night, and the hotel's private hot tubs are a good spot to watch for aurora if the forecast cooperates.

From Vík, Route 1 runs east across the Mýrdalssandur and Skeiðarársandur outwash plains, flat volcanic deserts that stretch to the horizon with almost nothing on them, before reaching Skaftafell in Vatnajökull National Park about 145 km along. We booked a 3.5-hour glacier walk on Svínafellsjökull through a local guiding outfit, crampons and ice axe included, for roughly ISK 18,000-20,000 per person; you cannot legally walk on the ice without a guide, and for good reason given the crevasses.

An hour further east, Jökulsárlón glacier lagoon delivers the trip's most photographed scene: icebergs calved from Breiðamerkurjökull drift silently toward the Atlantic, some the size of small buildings. Cross the road to Diamond Beach and you'll find fragments washed up on black sand, glinting like scattered glass.

We stayed at the Fosshotel Glacier Lagoon, a five-minute drive from Jökulsárlón itself, which meant we could catch the lagoon in soft evening light without racing the sunset. Doubles here run about USD 280-340 in shoulder season.

Höfn, about 80 km east of Jökulsárlón, is the self-declared langoustine capital of Iceland, and the harbor-side restaurant Pakkhús does not overpromise: their humar (langoustine) plate, priced around ISK 6,000-7,000, arrives in butter and garlic and needs nothing else.

Past Höfn, the road tightens into the East Fjords, where Route 1 hugs the coastline through Djúpivogur and a string of villages with more sheep than people. We took the short detour over Fjarðarheiði to Seyðisfjörður, a town of pastel wooden houses tucked at the head of a narrow fjord, best known for the rainbow-painted street leading to its blue timber church and for Hótel Aldan, a converted 1890s building where we had dinner overlooking the water.

This stretch of road is the least trafficked part of the entire loop. We passed maybe a dozen other cars in three hours, and the fjords themselves, streaked with waterfalls that have no name on any map, felt like the trip's best-kept secret.

From Egilsstaðir, Route 1 climbs inland toward Mývatn, roughly 260 km northwest, crossing terrain that turns increasingly volcanic as you go. A short detour north on Route 862 or 864 brings you to Dettifoss, which pushes more water over its ledge than almost any waterfall in Europe; the west-bank viewpoint gets you closer to the spray, the east-bank one gives the better full-frame photo.

Around Mývatn lake itself, the Námaskarð pass and the Hverir geothermal field steam and hiss with sulfur vents you can smell from the parking lot, a landscape that looks more like a film set than anything real. We ended the day at the Mývatn Nature Baths, the north's answer to the Blue Lagoon at a fraction of the price, around ISK 6,500-7,500 for entry, soaking in mineral-blue water while steam rose off the lake at dusk.

We slept in Reykjahlíð at Hotel Laxá, a modern build on the lake's edge with wide windows angled toward the northern sky, useful if the forecast for aurora looks promising.

Akureyri, Iceland's second city at around 20,000 people, sits an hour west of Mývatn at the head of Eyjafjörður. It's small enough to walk in an afternoon: the striking concrete Akureyrarkirkja church, the botanical garden Lystigarðurinn, and a solid lunch at Bautinn, a local institution for lamb soup and burgers since the 1940s.

From Akureyri we drove 50 minutes north to Húsavík for a 3-hour whale watching trip; humpback and minke whales are regularly sighted in Skjálfandi Bay between June and September, and boats run around ISK 13,000-15,000 per adult with thermal suits included.

The final push back toward Reykjavík covers close to 400 km, most of it on fast, well-maintained Route 1 through Blönduós and Borgarnes before the Hvalfjörður tunnel shortcuts under the fjord and drops you back into the capital's outskirts. We split this into a last night at Hótel Búðir on the Snæfellsnes Peninsula, close enough to see Kirkjufell mountain at sunset before the drive home the next morning.