What's the must-see thing in Zurich?

Fraumünster sits on Münsterhof, the quietest square in Zurich's Altstadt, about 400 metres from Zürich HB station. The church dates to 853 AD. But you're here for five stained-glass windows Marc Chagall completed in 1970. The nave is narrow, roughly 10 metres across, so the coloured light falls directly onto you rather than scattering into a cathedral void. Blues and greens from the 5 panels pool on the stone floor during clear mornings, while the reds take over on overcast days. Entry is 5 CHF (about $6 at current rates), no reservation needed. Fifteen minutes is enough. You might notice an Augusto Giacometti window from 1945 on the north transept, though the Chagall set overshadows it for good reason.

Cross the Münsterbrücke, about 200 metres east, and you're at Grossmünster. The twin-towered Romanesque church was completed in 1201. The church itself is free to enter. The Karlsturm tower costs 5 CHF for a climb of around 187 steps up a tight stone spiral where your shoulders brush both walls. At the top, Lake Zurich sits due south, the Limmat cuts through the Altstadt below, and on clear days the Glarner Alps line up about 70 kilometres away. August in Zurich currently pushes past 32°C by afternoon, so the cool air at the summit feels earned. The tower opens at 10:00 and closes at 17:00 in summer. Go before noon to dodge the school groups that tend to arrive after lunch.

Kunsthaus Zürich, founded in 1819, sits on Heimplatz about 800 metres uphill from the river. The 2021 David Chipperfield extension roughly doubled the gallery space. The Giacometti room holds the largest Alberto Giacometti collection anywhere. Thin bronze figures stand in quiet rows, each barely wider than your forearm. Monet's water lilies fill one wall. Munch is here too. The permanent collection alone needs about 2 hours. Entry is 23 CHF for adults (around $28), free on Wednesdays. Worth noting, Zurich gets around 130mm of rain across August, so you'll likely need an indoor afternoon at least once. The café on the ground floor serves passable coffee for 5.50 CHF while rain streaks the floor-to-ceiling windows onto Heimplatz.

Skip the Zürich Zoo on a first visit. It's in Fluntern, 20 minutes by tram from the center, and you'll spend 3 hours there that are better used in the Altstadt. National Museum Zurich, founded in 1898 in a castle-shaped building beside Zürich HB, is solid but demands a half-day commitment. If you have one day, the sequence is Fraumünster first, Grossmünster tower second, then Kunsthaus. All three sit within a 15-minute walk of each other along the Limmat. End the day at Zeughauskeller on Bahnhofstrasse. A plate of Zürcher Geschnetzeltes, sliced veal in cream sauce with rösti, runs about 38 CHF. The room smells like butter and old wood, and the building has served food since 1487.