You'll visit terraced vineyards carved into mountainsides with Matterhorn views at 900-1,200m altitude through Alpina Tour (www.alpina-tour.com, €250 per person). At Morgex et de La Salle (1,200m), ask the guide: 'Show me an ungrafted vine.' They'll point to gnarly roots going straight into the ground — no graft union, no American rootstock. When phylloxera killed 90% of European vineyards in the 1860s-1890s, these survived because the bug can't live above 900m altitude. Valle d'Aosta saved European wine genetics by accident of geography. Tour departs 9:00-13:00, includes transport, 3 wineries, tastings of 8-12 wines — Prié Blanc, Petit Rouge, Fumin, Muscat de Chambave.
🔄 BACKUP: If group tour unavailable, rent a car and DIY to La Crotta di Vegneron (Chambave) - cooperative of 70 growers, tastings €8. Or e-bike tour (€350, more intimate).