Few caves on earth have earned a place in the textbooks the way this one has. Denisova Cave sits on a limestone slope above the Anuy River in the northwestern Altai, and the story goes that it took its name from a hermit called Dionisy, Denis in the local speech, who lived here in the eighteenth century. What matters now is what lay in the floor. In 2010 a tiny finger bone from these deposits turned out to belong to a human group nobody had known about, the Denisovans, and later work showed that Neanderthals, Denisovans and modern people all passed through this same chamber at different times. You are standing where three kinds of humanity took shelter from the same winters.
Getting here is half the point. From Belokurikha you work west and north through the foothill farmland towards Soloneshnoye, the last proper town on the way with some four and a half thousand people, and that is where you should fill the tank and buy water, because the village of Topolnoye further on is small and the final miles are rural road and track. Expect a mix of tired asphalt and gravel, the odd cattle crossing, and a surface that turns greasy after rain. A light bike with sensible tyres is happier here than a loaded tourer, and the mood is of a valley that sees few visitors outside summer.
The Anuy valley itself is gentle country of birch, pine and meadow rather than the dramatic peaks you meet further south in the Altai, with the river running clear over stones and the slopes holding the grass smell of a dry continental summer. Late spring and early autumn are kind, the first with fresh green and the second with gold in the birches. July can be hot, and the cave mouth, cool and a little damp, makes a welcome shade.
Plan your visit with a bit of humility. This is still a working scientific site, so access to the interior depends on the day and the guides, and it is worth asking in Belokurikha or Soloneshnoye about the current arrangements before you ride the last stretch. Even if the gates are shut, the view from the slope, with the river curling below and the same horizon the cave dwellers had, makes the detour worth it. Bring a layer for the shade, eat before you come, and give yourself time to sit and look at a very old doorstep.