What's a good 3-day itinerary for Copenhagen?

Day 1 stays inside Indre By, the medieval core, where everything sits within a fifteen-minute walk. Start at Rundetårn by 9am — the spiral ramp (no stairs, which feels odd) leads to a rooftop panorama that orients you: copper spires east, Tivoli's wooden roller coaster south, harbor cranes north. Walk Købmagergade south to Gammeltorv, the city's oldest square, where the Caritas fountain has run since 1608. Lunch at Schønnemann on Hauser Plads — smørrebrød since 1877. The herring on dense dark rye with pickled onion and capers is the dish you came to Denmark for. Budget 180–220 DKK per plate, around $28–34. Nyhavn in the afternoon: yes, it's the postcard, and the canal-side restaurants are tourist-priced. Walk the colored-house side, skip those restaurants, grab a pølse from a cart instead. Tivoli from 5pm — the 1843 pleasure garden works better at dusk, when fairy lights come on and the smell of æbleskiver drifts across the gravel paths. Those round pancake puffs dusted in powdered sugar cost about 50 DKK ($8). Entry runs 155 DKK ($24). End at City Hall Square.

Day 2 heads north to the royal quarter. Rosenborg Castle first, by 9:30am — Christian IV built it in 1606 as a summer house that outlived the palace it was meant to supplement, and the crown jewels in the basement vault are worth the 130 DKK ($20). Kongens Have park outside will likely be full of sunbathers; in June the cut grass smells warm and green. Early lunch at Torvehallerne, the covered food hall near Nørreport: Coffee Collective for a flat white, Grød for porridge, Hallernes Smørrebrød for open sandwiches around 95 DKK ($15). Walk to Amalienborg for the noon guard change — worth timing if you can, skip if you can't. Then to Designmuseum Denmark on Bredgade, housed in a former hospital since 1907. The Danish chair collection sounds dry. It is not. From there, cut through Østre Anlæg park — laid out in 1870 — and north along the waterfront to Kastellet and The Little Mermaid. She is small. Everyone warns you and everyone is right. But the harbor light in the afternoon catches the bronze just so, and the walk through the star-shaped fortress to reach her is the reward.

Day 3 crosses the harbor to Christianshavn. A different city over there. Start at Church of Our Saviour by 10am and climb the external spiral staircase to the top. The last twenty steps narrow to single-file, the railing drops to waist height, and the wind off the Øresund hits hard. Not for vertigo. The view — 360 degrees, the whole Sound visible — is the best in Copenhagen, better than Rundetårn, and costs 65 DKK ($10). Walk through Christianshavns Torv to Freetown Christiania, the self-governing commune since 1971. It smells like woodsmoke and cannabis. The buildings are hand-painted. Go — it's historically significant, and Morgenstedet serves solid vegetarian lunch for about 90 DKK ($14). Pusher Street's photography ban is serious; keep the phone pocketed. Metro to Nørrebro after lunch — the neighborhood Copenhageners under forty call home. Jægersborggade is the street: natural-wine bars, ceramic studios, ramen at Slurp Ramen, coffee and a cardamom bun at Mirabelle bakery. Assistens Cemetery by late afternoon: Kierkegaard and Hans Christian Andersen are buried here, and locals treat it as a park, reading on blankets between headstones. That catches first-timers off guard.

Practical notes. Copenhagen runs on contactless — Visa and Mastercard work at every kiosk, bus, and pølsevogn cart. Many places no longer accept cash, which tends to simplify things. At the current rate of about 6.4 DKK to the dollar, budget roughly 600–800 DKK ($93–125) per day for meals and entry fees. A Rejsekort transit card with a 50 DKK deposit halves the per-trip cost over single tickets. The three days above total about 26 km on foot, heaviest on Days 1 and 3. June weather is currently sitting around 22°C with long light past 10pm — but a rain shower can materialize in twenty minutes, so a packable jacket earns its suitcase space. That late-evening sky, turning pale gold over the harbor around 9:30pm, is reason enough to push dinner to 8pm and eat outside.