Prague hands away its best views for nothing: castle courtyards, riverside orchards, and Gothic bridges cost zero. Add 190 CZK lunches in workers' canteens, 40 CZK trams and a 24 CZK boat, and three days here run cheaper than one in Vienna.
The 10th-century rival castle on a rock above the Vltava. Grounds and ramparts are free and open 24/7; the Slavín cemetery (Dvořák, Smetana, Mucha) opens 08:00, and St Peter & Paul's neo-Gothic spires charge 100 CZK inside.
A stand-up jídelna two minutes from Old Town Square where locals still eat: order at the counter with a paper card, pay on the way out. Goulash with dumplings around 145 CZK, soup 45 CZK, no cover charge, no tipping expected.
Skip the 145 CZK Vrtba entry and climb the free terraced Petřín slopes instead: Seminářská zahrada holds 2,100 fruit trees, blossoming pink in April. Paths from Újezd to the Hunger Wall are open dawn to dusk, year-round, at no cost.
Charles IV's 1360s fortification, 1,200 m of it still standing across Petřín, reputedly built as famine relief work. The wall path is unfenced and free; benches face east over the Lesser Town rooftops as the light turns.
Prague's biggest neighbourhood market runs Wed–Sat under Plečnik's brick Sacred Heart church. Moravian cheese, 30 CZK pastries, hot bramborák for 70 CZK. Vinohrady prices sit well under anything inside the tourist ring.
Tank Pilsner Urquell at roughly 55 CZK per half-litre and daily lunch menus around 190 CZK, in a Karlín backstreet rather than the Old Town. The beer arrives unpasteurised from steel tanks, poured in four traditional styles.
The hillside beer garden in Riegrovy sady pours half-litres for about 60 CZK at plastic tables full of students. West-facing slope, open roughly April–October from noon; sausages run 90 CZK, no reservations, no service charge.
Container-built food yard where stalls trade in the 150–250 CZK band, plus free live music most evenings. Nearby Billa and Albert supermarkets sell 25 CZK bread and 40 CZK cheese for a picnic if even that runs high.
The cheapest sightseeing in Prague: a 90-minute transit ticket costs 40 CZK and tram 22 climbs from the New Town past the National Theatre, over the river and up the Castle hill hairpins to Pohořelec, every 8 minutes.
Free parkland ridge above Karlín crowned by the world's third-largest bronze equestrian statue, Jan Žižka on horseback, cast in 1950 at 9 m tall. The escarpment path gives an uninterrupted skyline over the whole Old Town.
Prague's public ferries count as normal transit, so a 40 CZK ticket — or 24 CZK short-hop — buys a Vltava crossing to the long river island of Císařská louka. Wooded riverbank, swans, and a beach-like southern tip.
The concrete embankment below Vyšehrad turns into Prague's open-air living room after work: people sit on the wall with bottles from the nearby potraviny, and the restored vaulted cellars host cheap bars and Saturday markets.