The Strominger-Yau-Zaslow conjecture. If $X$ and $\check{X}$ are a mirror pair of Calabi-Yau $n$-folds, then there exists fibrations $f:X\rightarrow B$ and $\check{f}:\check{X}\rightarrow B$ whose fibres are special Lagrangian, with general fibre an $n$-torus. Furthermore, these fibrations are dual, in the sense that canonically $X_{b}=H^{1}(\check{X}_{b},\mathbb{R}/\mathbb{Z})$ and $\check{X}_{b}=H^{1}(X_{b},\mathbb{R}/\mathbb{Z})$ whenever $X_{b}$ and $\check{X}_{b}$ are non-singular tori.