 The fourth stage of the race was the longest of the race : a 204 km ( 126 @.@ 8 mi ) route from Varennes @-@ sur @-@ Allier to the Col de la Croix de Chaubouret , the only summit finish in the race . The route was hilly throughout , with two second @-@ category and five third @-@ category climbs before the final ascent . The Col de la Croix de Chaubouret was the highest point in the race at 1 @,@ 201 m ( 3 @,@ 940 ft ) , making this the queen stage of the 2015 Paris – Nice . It was a 10 km ( 6 mi ) climb averaging 6 @.@ 7 % , with some sections at 9 % . 
