St Gotthard Pass - 2109 metres
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     photo by: Sheila     
     photo by: Francis     
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On the new road, on the easier north side.

Climbing, the new road is best on this side, though the cobbled old road is OK if descending.
Most of the way there's no choice anyway.

The south is different - on the lower slopes there are signs forbidding cycling on the newer road, so you should climb on the cobbles, which is quite hard going.
There are opportunities to switch from one to the other about halfway up, but after that the roads take completely different routes, not meeting again until after the summit.