The Sukkulenten-Sammlung — Zurich's municipal succulent collection — is one of the most globally significant living plant collections in any city, with more than 6,500 species across seven greenhouses. It sits beside the lake at Mythenquai, free to enter, open every day, and has become a slightly cult attraction for visitors who want something quieter than the standard museum circuit.
The greenhouses are divided by climate region: South African, Mexican, Madagascan, South American. Highlights include the Yemeni dragon trees, ancient cushion-shaped Lithops, and, in summer, the rare night-blooming "Queen of the Night" Selenicereus, whose huge perfumed flowers open for a single evening — a much-anticipated annual event the gardens publicise in advance. About an hour for an unhurried walk through the houses; longer if you sit by the lake afterwards.