Gotland's improbably mild climate — sometimes called "the rose island" because the roses flower as late as December — supports plants that should not grow this far north. The botanical garden, laid out in 1855 just inside the northern stretch of the city wall, takes full advantage. Fig trees, mulberries, monkey-puzzle trees, magnolias and a serious collection of roses all thrive here.
It is a free, mostly volunteer-run space, organised by a local horticultural society. Open year-round, but best in late May when the wisteria is in bloom and the medieval church ruin in the middle of the garden becomes a wisteria-draped backdrop for the lazier kind of summer afternoon.