Recommended for keen weekend cyclists looking for a challenge, days are well-paced. You’re on the road for between six and eight hours each day, 10 on a couple, and not all of the route is steep. Though narrow, the roads are generally traffic-free and the spectacular views always diverting. You will be exposed to high altitudes, however, with the route reaching between 2,000ft (610m) and 12,400ft (3,700m). A support vehicle is always on hand for anyone who's flagging.

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The world's bravest travel adventures