In [Shi86], Shi proved Lusztig's conjecture that the number of two-sided cells for the affine Weyl group of type A n−1 is the number of partitions of n. As a byproduct, he introduced the Shi arrangement of hyperplanes and found a few of its remarkable properties. The Shi arrangement has since become a central object in algebraic combinatorics. This article is intended to be a fairly gentle introduction to the Shi arrangement, intended for readers with a modest background in combinatorics, algebra, and Euclidean geometry. After background material in Section 1, this introduction to the arrangement will be by way of a discussion in Section 2 of how it arose, some of its marvelous enumerative properties in Section 3, and some of its surprising connections to algebra in Section 4. For some brief comments on recent extensions, see Section 5 and for an incomplete list of topics we left out, see Section 6.