FRANCE: Elephant Walk

Ever since Hannibal, the boy-wonder general of ancient Carthage, performed the astonishing feat of leading 37 elephants and an army of some 45,000 over the Alps into northern Italy to attack Rome in 218 B.C., experts have speculated on what route he took across the mountains. Unlike Caesar, Hannibal penned no commentary, and experts have had to make do with the later writings of Polybius and Livy.

From such clues, students have proposed dozens of alternative routes. In Alps and Elephants, published in 1955, Britain's Sir Gavin de Beer casts his vote for the Col de la Traversette, but analyzes...