The 4th stage will take place exclusively in the Tuscan territory, 42 km left at the end of the challenge We start immediately with the Sambuca pass, after just 1km from the beginning the road starts to climb decidedly away from the valley floor. The valley is always wide and clearly visible, wide views also favored by the almost total absence of tall vegetation. After about 9 kilometers of ascent we reach the foot of the pass, the last stretch of the journey of about 2 kilometers appears to us almost entirely. Almost a wall, which we must overcome with a series of switchbacks and short straight stretches almost dug into the side of the mountain. The summit is now close A few curves and we reach the Sambuca pass Mt. 1061 - total height difference from the start mt. 634 in 10.8km On the step stele in memory of the fallen of the 36 'Garibaldi brigade. Continuing south, you will now find 2km of beautiful descent which, following a wide tree-lined valley, reaches the Rovigo ditch (930 m), followed by a 1.8 km ascent to Prato all’ Albero that will delight you with a great view over the Mugello From here 17km all downhill to Marradi where there will be nothing left but the last 12km already covered in the second stage.