Porto district, Portugal

EM 593, Penafiel

Three and a half kilometres of hill road through the villages and vineyards north of the Douro.

A narrow municipal road that drops 87 metres between small fields, vines and 600 houses, with 28 junctions on the way. The roadside comes from Portugal's 2018 aerial survey. Grades reach 10%, and there is barely a straight in it.