From Arabba, take the Gorza cable car to the upper station. This puts you at the highest point on the Sellaronda
at 2465 m (8090 ft). As you step off the lift, you'll see the snow-capped Marmolada peak, which is the highest point in the Dolomites at 3343 m (10668 ft).
During World War I, the Italians and Austro-Hungarians fought over this territory, including on the Marmolada Glacier itself. It is this tragedy that we have the war to thank for many of the roads and trails in this area. Also, the regions of Trentino and Alto Adige (Südtirol in German) were part of the Austro-Hungarian empire until this point; thus the reason German is commonly spoken in this region.
From the top of the Gorza cable car, follow the only gravel road down; you'll lose 1000 ft in the next 1.5 miles. You'll have great views of Piz Boe and the Sella Group all the way to Passo Pordoi.
If you want to skip the climb to the Passo Pordoi, you can continue downhill on the gravel road to SR48: turn right and follow it to the Fodom lift which will take you to the pass. But this would miss a really fun section of singletrack.
Instead, after the initial 1.5 mile descent on the gravel road, continue straight onto the singletrack which begins a 500 foot climb to the Passo Pordoi. This trail has a bit of a cross-slope until you reach the SR48, so this is more challenging than the previous segments of the Sellaronda
. When you reach SR48, turn left to finish the climb to Passo Pordoi, which is the highest of the four passes forming the Sellaronda
at 2241 m (7350 ft).
Towards the back of the parking lot on the other side of the Passo Pordoi, there is a (mostly) singletrack that begins a 3.5-mile downhill section. Part of this trail follows the 4x
downhill track, which takes you to the next town of Canazei.
In Canazei, follow the SS48 about two miles down to the next town, Campitello di Fassa, where you should take the Col Rodella cable car for the next segment of the Sellaronda