Back when the Ionian Empire ruled Fellport, the harbor held warships and troop transports intent on spreading the empire's influence. Bored sailors and soldiers often argued about the most insignificant differences, but mostly about which were better, faster, or stronger. The officers got together and decided to organize games to take mortality out of these conflicts and put their troops on a path of self-improvement instead.
Both groups used the Arena as a neutral area, though most of the time the gladiators practiced or performed there, so these arena games rarely happened. The army organized all sorts of team games outside the walls on the field now built up as the Fairgrounds. The navy decided to stack the deck in their favor, so they came up with Gostra.
Imagine a 50-foot-tall ship's mast. Now stick it into the ground at a low angle so it hangs out over the harbor. Slather it with four gallons of grease and lard, then hang three flags from it, the furthest at the very end. Now let the strongest, fastest, and most dexterous run up the pole and grab the flags for prizes, and watch the comedic plummeting. The person who grabs or gets closest to the flag at the far end gets bragging rights until the next game of Gostra. Everyone ends up in the harbor at some point, and divers make sure they're OK. Traditionally, competitors call out the name of a god on their way up the pole, and any flag they capture gets dedicated to that god, but this practice largely faded over the past century. Now the prizes reign supreme.
The traditional Running of the Gostra Pole goes back at least 400 years, but now it happens yearly near the end of summer. It started as a military exercise to maintain morale and prevent fights, but it opened up to anyone who wants to try it. The Gostra Festival takes place over the course of three days, with crowds lining the breakwater, many vendors selling food and party favors, and a crowd of boats circling the pole from the water. Even the Pirate's Spire rents out cells with windows to watch the competition from above. The organizers award prizes for the top finishers, and many private donors give their own awards.
Over the past few years, Festive Frocks, one of the largest clothiers and costumers in Fellport, have given the Coveted Costume Award for the best-dressed competitor, regardless of how well they do on the Gostra Pole. Winners get a consultation with one of their designers and credit toward a bespoke outfit, or a sizable cash prize.
Note: I lifted this wholesale from the real-world game Maltese game of Gostra, just with a different origin story. And with its popularity in Fellport, everyone wants a piece of the publicity pie.