Water mattered in medieval Pisa. As it was not a natural port, Pisa had to protect, manage, and maintain its maritime landings and riverine passages to neutralize its Mediterranean competitors and ensure its prosperity. This paper addresses the three bodies of water and waterways most important to the Pisa - the Tyrrhenian Sea and the Auser and Arno rivers - and how architecture interfaced with hydrotopography. Architectural structures defined a unique visual culture in Pisa in practical, topographical, and symbolic ways. (...) The organization of the city, its key monuments, and their ornamentation all demonstrated the significance of the city’s complex relationship with water that was key to Pisa’s success in the Middle Ages. (shrink)