Regions to know
To frame your trip by what you have time for and what you're after.
Reykjavik & Reykjanes
Reykjavik, Blue Lagoon, Reykjanes peninsula volcanoes
The capital + the airport region. All international flights land at Keflavík (KEF, 50min from Reykjavik). Use Reykjavik as base for day trips, or grab a rental car immediately and start the Ring Road.
South Coast
Golden Circle, Seljalandsfoss, Skógafoss, Vík, Jökulsárlón, Diamond Beach
The iconic strip. 80% of Iceland's bucket-list sites are on or just off Route 1 between Reykjavik and Höfn. Doable as a 4–5 day out-and-back if you don't have time for the full Ring Road.
North & East
Akureyri, Mývatn, Húsavík (whale watching), Goðafoss, Dettifoss
Iceland's quieter half. Akureyri is the 'capital of the north' (20,000 people). Mývatn area has another set of waterfalls, lava fields, the Nature Baths. Húsavík for whale watching (best Apr–Sept). Add 3–4 days if you do the full Ring Road.
Westfjords
Ísafjörður, Látrabjarg, Dynjandi, Hornstrandir reserve
The remote northwest peninsula. 1/3 of the country, 7,000 people, the wildest landscape. Dynjandi waterfall, Látrabjarg cliffs (puffins). Mostly accessible only June–September; takes 2–3 days to fit in.
Highlands (Hálendi)
Landmannalaugar, Þórsmörk, Askja, Kerlingarfjöll
Iceland's interior — uninhabited, lunar, only open mid-June to mid-September. 4x4 mandatory; F-roads require river crossings. Where the Laugavegur trek (55km, 4 days) and Apollo astronauts trained for the moon. Adventure-tier travel.
Snæfellsnes peninsula
Kirkjufell, Snæfellsjökull glacier, Búðir black church, Arnarstapi
Iceland in miniature, 2 hours from Reykjavik. Doable as an overnight loop — black-sand beaches, lava fields, Snæfellsjökull glacier (Jules Verne's Journey to the Center of the Earth). Worth a day or two even on a short trip.