The Sapporo Snow Festival — Yuki Matsuri — runs for about a week every February and draws over two million visitors to what is already a heavily snowed-in city. The main event is in Odori Park, where twelve blocks of the central green space are filled with enormous snow and ice sculptures, some of them the size of multi-storey buildings, carved over weeks by teams of specialists, military units, and international competitors. The range goes from technically extraordinary — detailed reproductions of famous buildings and scenes from history — to frankly odd, but the sheer scale carries it. A second venue in Susukino focuses on ice sculptures illuminated at night, which is the better evening activity.
The festival started in 1950, when local high school students built six snow statues in the park as a winter activity. It grew steadily until the 1972 Winter Olympics put Sapporo in front of an international audience and the event became a national institution. Visiting in festival week requires booking accommodation well in advance; prices spike and rooms in central Sapporo sell out months ahead. If you can't make the festival itself, Sapporo in February is still worth visiting — the city handles heavy winter conditions with the matter-of-fact competence of somewhere that has no choice in the matter.