Stage 19: Caso. Parque Natural de Redes to Gijón, 149.7km
A leg-breaker: periods of idling interspersed with hard climbs and descents. It'll be worse if it rains, as it tends to in so-called 'Green Spain'. The 153km stage covers four climbs. The final obstacle, 17km from the line, is the Alto de San Martín. It's only a cat-3, but adds complication. The stage finishes with an 8km flat run into Gijón.