Things to do — Þingvellir

Almannagjá fissure trail (1 km, 30-45 min). The most emblematic trail: descend into the geological fissure formed by the separation of tectonic plates and walk between the rock walls. Trilingual interpretive panels at several points. Accessible to strollers (gentle slope, stabilised ground).

Lögberg (Law Rock) and flag (15 extra min). At the end of the fissure, climb the small hill with the Icelandic flag: it is here that the lawspeaker (Lögsögumaður) recited all the laws aloud during the Alþingi. Panorama over Lake Þingvallavatn and surrounding mountains.

Öxará river and Öxarárfoss waterfall (15 extra min). Continue the trail upstream to the small Öxarárfoss waterfall (8 m drop) — quieter and more photogenic site.

Þingvellir church (free, open June to August). Small 19th-century wooden church on the site of the first Christian church of 1000. Mausoleum of national poets Jónas Hallgrímsson and Einar Benediktsson in the cemetery.

Hakið visitor centre (free, open year-round). Multimedia exhibition on the geology and history of the Alþingi, souvenir shop, cafeteria, toilets. Ideal to start or end the visit.

Silfra snorkelling/diving (€130-180, 2 h, mandatory booking). The flagship experience: swim between two tectonic plates in crystalline water filtered by basalt rocks. Drysuit provided, mandatory professional supervision (Dive.is, Arctic Adventures, Iceland ProDive). Accessible to non-divers in snorkelling.

Lake Þingvallavatn (84 km², Iceland's largest natural lake). Several viewpoints from car parks P2 and P5. Unique Arctic char population (4 endemic morphs studied by world biologists). Possibility of fishing in season (permit required) or simple walk along the water.

Additional trails (for hikers): trail to Mount Skjaldbreiður (shield volcano 24 km away, full-day hike), trail to Flosagjá fissure (parallel to Almannagjá, less frequented).