The Sundgau in 4 days

Ruins on a 612-metre rocky peak above Ferrette, seat of the Counts of Ferrette, among the most powerful lords of Upper Alsace before the Habsburgs.

A forest path between Ferrette and Bouxwiller leads to limestone cliffs, a 25-metre gorge and a small cave that legend says housed the earth dwarves.

A restored farmhouse with exposed half-timbering, showing rural Sundgau life in the 19th and early 20th centuries through trades, looms and household objects.

A hilltop castle at Leymen by the Swiss border, older than 1297, later modernised by Vauban and used as a state prison until the Revolution.

The 217 km river that runs through Mulhouse and Strasbourg begins here in the meadows at around 550 metres, narrow enough to step across.

First mentioned in 1183, on a 522-metre hill a kilometre from Switzerland, destroyed by the 1356 Basel earthquake and rebuilt as an artillery fortress.

An English-style park laid out in the early 19th century by Charles de Reinach around his family's listed manor, with large trees and wide lawns.

The Sundgau's capital, founded in the 12th century above the Ill, where most of the castle made way for the church in 1845.