Breche de Roland
A deep defile in the crest of the Pyrenees, some three hundred feet in width, between two precipitous rocks. The legend is that Roland, the paladin, cleft the rock in two with his sword Durandal, when he was set upon by the Gascons at Roncesvalles.
Then would I seek the Pyrenean breach Which Roland clove with huge two-handed sway.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894