This paper presents twelve illustrative Petri nets developed for educational purposes to teach the fundamentals of system modeling. Inspired by an exercise by Wil van der Aalst on Brisbane’s CityCats, these models are grounded in realistic systems rather than purely abstract constructions. Each Petri net captures the dynamics of an everyday technical or social process – from radiator fans and digital clocks to espresso machines and population growth – and is characterized according to structural and behavioral properties such as free-choice, safety, boundedness, liveness, and sequentiality. The collection can be used for classroom exercises, examinations, and demonstrations of Petri net analysis techniques, including reachability and coverability graphs. All models were created using the WoPeD tool and are available in PNML format for download and reuse.