Research on the (cyber) security of industrial control systems requires holistic understanding of practical systems in the field. In particular, important differences to IT security scenarios are related to industrial networking protocols and programming languages such as ladder logic. Arguably, access to realistic testbeds with physical process and related controls would enable researchers to understand the scenarios better, to develop attacks, and test countermeasures. While the implementation of such testbeds presents significant investments and efforts, the implementation process itself is often not discussed in literature. In this chapter, we discuss the design and realization of such industrial control system testbeds for security research. In particular, we discuss a process in which testbeds are designed by security researchers to resemble existing (and future) plants, and are then implemented by commercial system integrators using industry’s best practises. As use cases, we provide details on design decisions, cost, and outcomes for three testbeds established at the Singapore University of Technology and Design.