United States of America

The Loop on U.S. 441, Great Smoky Mountains Nat. Park.
Old post card picture of the same spot: external link

More specifically - pigtail bridge in the Black Hills

Black Hills, SD

japan

montenegro

Mallorca

Basel?

National Geographic

This looks to be a far from recent photo of the loop that an Anonymous already listed - US Rt. 441 in the Tennessee side of the Great Smokey Mountains National Park, about 6 miles/10km southeast of Gatlineburg. The entrance/exit turns are dead-on for it and the pull-off area in the loop is visible in street view (albeit apparently disused and leaf covered.)

Great Smokey Mountains, Tenn to North Carolina

I've seen this in Tenerife, Canary Islands, Spain. It was on the skirts of Mt. Teide, but i couldn't tell the road number.

so eine Strasse gibt es auch im Westen Mallorcas (sa Calobra), aber dort sind wohl viel weniger Bäume, wenn ich mich recht erinnere.