Rugbraud is a dense, dark and slightly sweet Icelandic rye bread, traditionally steam-baked for many hours. In some places it is still buried in geothermal ground to cook, earning the nickname thunder bread.
Where to eat it: 3 restaurants across 1 city.
Rye grew where wheat could not, so dark rye bread became the everyday loaf of Iceland. The most famous version, hverabraud, is baked by burying a covered pot in hot geothermal soil near hot springs and leaving it for up to 24 hours, producing a moist, almost cake-like loaf. It is served sliced thin with butter, smoked lamb or pickled herring. In Reykjavik you find it at Cafe Loki and the old bakeries, and even as a rye-bread ice cream.
Common allergens: Gluten
Why locals love it: Most visitors photograph Hallgrimskirkja and leave, missing the small cafe opposite that serves the city's most accessible traditional Icelandic plates.
Tip: The easiest place to try rye bread with mashed fish and rye-bread ice cream. Walk-in only.
Sandholt on Laugavegur serves an all-day bakery brunch in Reykjavik, with shakshuka, sourdough toasts and savoury waffles by the pastry counter.
Order: The shakshuka, or sourdough toast piled with eggs and cheese.
Tip: The pastries come straight from the bakery in the same room. Arrive early at weekends to beat the queue.
Bernhoftsbakari, founded 1834, is Iceland's oldest business, a Reykjavik bakery now run by the fifth generation and stocked with snudur and kleinur.
Order: A snudur, the Icelandic cinnamon bun, or a twisted kleina doughnut.
Tip: Iceland's oldest continuously operating business, on Klapparstigur. The traditional pastries are the draw.
Worth the queue: Snudur cinnamon bun
More cities are in research. Want rugbraud (geothermal rye bread) covered somewhere specific? Tell us where you want to eat.