St Stephen's Cathedral

The Stephansdom is Vienna's compass and its nickname-bearer — der Steffl, the south tower every Viennese orients by, 137 metres of Gothic ambition finished in 1433 and never matched by the north tower (funds and faith ran out; its Renaissance cap sits at half height like an apology). The glazed-tile roof is the cathedral's signature: 230,000 tiles in chevrons and the double-headed imperial eagle, steep enough to self-clean in rain, rebuilt by public subscription after the 1945 fire that gutted the building in the war's last days — every province funding a piece, which is why the roof reads as the national quilt it is.

Inside, the free nave view satisfies most visits, but the ticketed layers hold the stories: Anton Pilgram's carved pulpit with the sculptor himself peering from a window beneath it ("the window-gawker," signing his work with his face); the catacombs tour descending to bishops' crypts and the bronze urns holding Habsburg innards (the dynasty distributed itself across three churches — hearts, bodies, entrails — and this is the entrails address, delivered deadpan by the guides); and the two tower experiences — the south tower's 343 medieval steps to a cramped watchman's room with the best roof-tile close-ups, or the north tower's lift to the Pummerin, the great bell cast from captured Ottoman cannons that rings in every Austrian new year.

Mozart's life bracketed itself here — married 1782, his funeral blessed in a side chapel 1791 — and the evening organ and orchestral concerts inside continue the parish's long employment of genius; the giant-organ recitals suit the space absurdly well. Go at 8 AM when the nave is incense and locals, or for a concert after dark; midday belongs to the tour flags. The all-inclusive ticket (audio guide, catacombs, both towers) is the efficient buy for completists; the €0 option — standing under the roof at Stephansplatz as the bells argue — remains Vienna's most reliable free thrill.