At 92, Al Frediani is a link to Napa's past. So is his vineyard. The nonagenarian is hard of hearing and moves and talks slowly, but his memory and wit remain sharp as ever. His 20-acre vineyard, tucked away in the northeast corner of the valley on a quiet dead-end road, is one of Napa's oldest. Local winemakers call it "magical." Wine Spectator's MaryAnn Worobiec explains.