Lago Blu is a tiny mountain lake just below Cervinia on the road up from Valtournenche, famous out of all proportion to its size for one reason: on a still morning the Matterhorn reflects in it almost perfectly. The lake is fed by snowmelt and its colour shifts from deep blue to turquoise depending on the light and the season.
It's an easy stop — a small layby on the road, a flat walk to the water — and unfailingly photographed. Early morning before the wind picks up is when the reflection works. In winter the lake freezes over and the magic is gone, but the surrounding pine forest is itself worth the short stop.