The Number [Pi] by Pierre Eymard, Jean-Pierre LafonCall Number: QA484 .E9613 2004; SAL3
This is a clever, beautiful book. The authors trace the thread of $\pi$ through the long history of mathematics. In so doing, they touch upon many major subjects in mathematics: geometry (of course), number theory, Galois theory, probability, transcendental numbers, analysis, and, as their crown jewel, the theory of elliptic functions, which connects many of the other subjects.