Downtown Reykjavik is small enough to walk end to end in twenty minutes, which is either a limitation or a gift depending on how you use it. I treat it as the latter, and I start every visit the same way: at Hallgrímskirkja, the concrete church that looks like it was designed by someone who took the word "tower" as a personal challenge. Take the elevator up. The view from the top puts the whole city in its proper context, a low-slung grid of colored rooftops pressed between mountains and the North Atlantic, and that context matters before you start wandering. From there I walk down Skólavörðustígur toward the old harbor and let the street do its work. The shopping along this stretch is genuinely worth your time if you know what you are looking for: real Icelandic wool, not the machine-made stuff with a Viking logo stitched on for tourists, and local ceramics from the smaller studios that will actually survive in your carry-on without becoming gravel. I stop when something earns it and move on when it does not.
Lunch is not a question. Messinn, on Lækjargata, serves pan-fried fish that makes a clear argument for why you came this far north in the first place. Order the catch of the day. Budget somewhere between 4,000 and 6,000 ISK for a proper sit-down meal, which feels steep for about thirty seconds until you remember what the food actually tastes like and what the alternative is. After Messinn, or honestly after any morning of walking into cold harbor wind, I stop at Bæjarins Beztu Pylsur. The hot dog stand near the harbor has a reputation that sounds like hype until you are standing there eating one with everything on it, and then it makes complete sense. The cases where street food folklore actually delivers are rare enough that this one deserves acknowledgment. For coffee, Reykjavik Roasters on Brautarholt is the only answer I have found that holds up across multiple visits. The chains near Austurvöllur are convenient in the way that convenience stores are convenient, which is to say, not really.
On the question of where to sleep, Holt is worth the premium if you want a hotel that feels like it was furnished by someone with actual opinions about Icelandic art and a preference for bars that are unhurried and a little dark. If the budget runs tighter, Kex Hostel is one of the most thoughtfully designed hostels I have encountered anywhere in the world, and its bar pulls in locals rather than just travelers comparing itineraries, which is the clearest possible sign you are in the right place. There are things I would skip without hesitation: the dinner spots on Austurstræti that survive on foot traffic rather than cooking. They are easy to find because they want to be found, which is usually the tell. Walk one block in any direction and the options improve considerably. The best restaurants in Reykjavik operate on a principle I recognize from the places I return to everywhere: no pretense, just execution, every time. That is the logic worth following here, and when you find a place built around it, eat there twice.
If your itinerary puts you in Reykjavik and nowhere else, reconsider the whole shape of the trip. The Golden Circle is a half-day drive and it earns every kilometer. Geysir, Gullfoss, Þingvellir, these are landscapes that recalibrate your sense of scale in a way that no city, including this one, can replicate. Spend your morning at the church and the harbor, eat fish at Messinn, and walk until something makes you stop. If you get more time than that, rent a car and leave the city for at least a day.
