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

Day 1 stays east of the Grand Canal. St Mark's Basilica dates to 828. It opens at 9:30am, but the line along Piazza San Marco's south flank starts forming by 9. The marble floor inside feels cool through thin shoes, and about 8,000 square metres of gold mosaic cover the domed ceilings. Walk straight into Doge's Palace next door, rebuilt in its current Gothic form around 1340. The Bridge of Sighs connecting it to the old prison stretches only 11 metres, far smaller than photographs suggest. Climb the Campanile after, first raised around the year 1000 and rebuilt brick by brick after its collapse in 1902. From the top, the Lido barrier island sits low across the lagoon to the east. Lunch at Rosticceria Gislon on Calle de la Bissa, a 4-minute walk north. A plate of fried seafood and a glass of house white runs about €15. By 3pm, cut through Castello's residential streets toward the Arsenale, where the brick walls of the old naval shipyard still smell faintly of tar and salt.

Day 2 crosses the Grand Canal to San Polo and Dorsoduro. Start at 7:30am at the Rialto fish market, the Pescheria, where vendors have sold the lagoon catch since 1097. The smell of brine and seawater hits before you see the stalls. It closes by noon, so arrive early. Walk 8 minutes south to Santa Maria Gloriosa dei Frari, a Franciscan church founded in 1250. Titian's Assumption of the Virgin hangs behind the high altar. The church is dim enough at 9am that your eyes need a moment to adjust. Cicchetti at All'Arco on Calle dell'Ochialer for lunch. Two or three small plates and a prosecco cost about €12. The Gallerie dell'Accademia, open since 1750, holds 5 centuries of Venetian painting across 24 rooms. Plan about 90 minutes. On your way south, step into Santa Maria della Salute, the domed church Longhena began building in 1631 as a vow against the plague. Finish at the Zattere waterfront by 7pm, where the stone promenade faces the Giudecca Canal and the low sun warms the flagstones underfoot.

Day 3 starts in Cannaregio, Venice's northernmost sestiere. Ca' d'Oro, a Gothic palazzo built in 1424, opens at 8:15am. The facade was originally covered in gold leaf, and patches of the stonework still look warmer than the neighbouring buildings. Walk east along Fondamenta della Misericordia, where the morning light hits the canal at a low angle and the bars are still setting out chairs. From Fondamente Nove, take the line-12 vaporetto to Murano. The ride takes 20 minutes. A single ticket costs €9.50, or a 24-hour pass covers unlimited rides for €25. Glass-blowing demonstrations on Murano run about 15 minutes and cost nothing. Continue on the same line to Burano, 30 minutes further, where houses are painted in regulation colours assigned by the local government. Lunch at Trattoria al Gatto Nero on Fondamenta della Giudecca. A plate of risotto de gò, made with lagoon goby fish, costs about €22. The return vaporetto from Burano to Fondamente Nove takes 45 minutes.

These three days cover about 20 kilometres on foot. Venice has no cars, no bicycles in the historic centre, and no flat alternatives to its 400-plus bridges. Comfortable shoes with grip matter more in Venice than in most European cities, because the stone bridge steps get slick after rain. July temperatures currently sit around 27°C with moderate humidity. The narrow calli provide shade, but the open piazza at San Marco does not. Fill water bottles at any public fontanella, which run continuously with potable water. Buy the 24-hour vaporetto pass for the island day and walk the rest. At the current rate of about $1.14 to the euro, daily spending on entries, meals, and transport runs roughly $80-90. Santa Lucia station to the Arsenale is about 4 kilometres, a walk of roughly 50 minutes without stopping.