The Portes du Soleil, which spans the French-Swiss border, linking 13 ski areas with 650km of pistes has at times in its 50 year history claimed to be the biggest ski area in the world.
The problem is that unlike the 600km(ish) of the 3 Valleys, those 650km are not fully lift and piste linked, you need to get a bus between separate sectors. Not really a big issue in reality but ski statisticians do tend to get pedantic about such things, and if you allow one bus link in a claimed piste kilometrage tally, where do you draw the line?
This winter the region has invested €16 million in a huge project to bridge one of those gaps, to Super-Chatel, with two new high speed detachable chairlifts coming into service, a 6-seater and a 4-seater. The link is partially completed with a new piste to follow, so there’ll be more than 650km then.
