Cross Every Bridge Once: The One-Stroke Town Puzzle

Can you design a town that can be explored in one continuous journey without crossing any bridge twice? Turn network mathematics into an original puzzle that another student can trace, test, and solve. 🌟 COMPETITION OVERVIEW Create a fictional town with five locations and seven bridges or paths. Your network must have a valid route that crosses every bridge exactly once. The finished entry should challenge a solver while also proving that the route works. 🎯 THE MISSION • Invent exactly five named locations, such as islands, parks, plazas, stations, or neighbourhoods. • Connect them with exactly seven bridges or paths. • Arrange the connections so one continuous journey crosses every bridge exactly once without repeating a bridge. • Present the unsolved puzzle first, followed by a numbered solution and a clear explanation. 🔍 WHAT TO INCLUDE • A clean puzzle map showing all five named locations and seven bridges. • Exactly two locations with an odd number of connected bridges. • A clearly identified starting location and finishing location. • A numbered route showing the order in which all seven bridges are crossed. • A short explanation of why the start and finish work. • A final check confirming that every bridge appears once in the solution. • Early learners may use colours, arrows, numbers, and adult-written dictated words. • Older students should use connection counts and explain why the two odd locations determine the route’s endpoints. 📋 RULES • Locations may be visited more than once, but no bridge may be crossed more than once. • Each bridge must connect two locations directly. • If two drawn bridges cross without connecting, mark the crossing clearly as “no junction.” • Use an original fictional layout. • Do not use real addresses, private locations, school maps, logos, or copyrighted characters. • Test the full route before submitting. • Keep the map readable and school-appropriate. • Upload exactly one file. 📤 SUBMISSION • Submit one PDF file containing no more than two pages. • Page 1 must show the clean, unsolved puzzle. • Page 2 must show the numbered solution route and explanation. • Do not submit separate attachments or links needed to understand the entry. 🏆 JUDGING CRITERIA • Mathematical validity and verified one-stroke solution — 35% • Elegance and challenge of the network design — 25% • Clarity of the puzzle map and solution route — 20% • Quality of the start-and-finish explanation — 10% • Originality, accessibility, and rule-following — 10% 🎁 WHY PARTICIPATE? This challenge turns an important idea from topology into a playable design problem. It develops spatial reasoning, proof, persistence, visual communication, and the ability to test whether a creative idea really works.