What a cool little mystery, and article! I'm glad that the answer is actually quite satisfying and poetic (and not, for example, some mundane artifact in manuf

What a cool little mystery, and article! I'm glad that the answer is actually quite satisfying and poetic (and not, for example, some mundane artifact in manufacturing the bollards). > Still, a question does remain, one that might never be answered. “There’s actually only one bollard that correctly points to those cities,” Muñoz Sainz says. The rest were installed without regard to the direction in which the pattern was positioned. At the time, no one cared too much. The bollard’s creator never told anyone the logic behind his design, until now. “And today even I don’t know where the correct one is… It’s been a long time.” This is a totally solvable problem. Given n bollards with coordinates, and m cities with coordinates, it should be quite fast to calculate which is the prototypical bollard. I'd explore this question if I had more time this weekend -- many upvotes if anyone else wants to tackle that! This article also introduced me to the online encyclopedia of integer sequences ( oeis.org ). As a computer scientist with a limited math research background I had no idea that this tool existed. The laundry list of applications it offers for the fibonacci numbers [1] is remarkable! Interesting to think of the sheer human achievement that was required to build that list. [1] https://oeis.org/search?q=1%2C1%2C2%2C3%2C5%2C8%2C13&language=english&go=Search https://oeis.org/search?q=1%2C1%2C2%2C3%2C5%2C8%2C13&languag...