The "Day's Walk" Race

Each summer, on the solstice, towns along the northern coast hold races to see how far inland competitors can travel between sunset and sunrise.

Observance

The race is not restricted to the fittest and fastest. Many people participate simply to be part of the event. There are prizes awarded to those who get the furthest inland though, so some take the race very seriously, planning and training throughout the year. Much fuss is made of those who have done well in previous years. Those not participating might take support roles, preparing food and water supplies at key locations.
On the morning of the race the participants assemble on the beach before dawn. The most competitive will be positioned close to whatever path or road leads up toward town. When the sun first peeks over the horizon the town mayor blows a starting whistle and the participants set off. Spectators (as the mayor usually is) will use horses to keep up with them. The serious racers will often reach town around noon. Here they will be met with cheers and encouragement. In most towns there is one main route inland from the town, often following the river to the nearest Elven city or village. Spectators will head out this way in the afternoon, using horses and carts to overtake the leading racers and then set themselves up along the track where they expect the racers to be at sunset, ready to cheer them on for the final stretch.
When at last the sun dips below the horizon, the mayor (who is usually riding alongside the furthest competitor at the time) blows a final whistle. The progress is marked with a large stone engraved with the year and the tired competitors are carried back into town. Celebrations ensue, with awards given to those who had travelled the furthest.
The Elves who live nearest to each settlement typically send a delegation the day before, as spectators. They will grant finely crafted awards to the man and the woman who travel the furthest and often give a small speech extolling the benefits of peaceful coexistence.

History

Many generations ago, when the Kingdom of Men had only just formed, humans began to travel around the coast and settle. The Elves, who made their home in the valleys on the northern side of the mountain range, met with these folks. They told them that the Elves would not object to their settlements, provided that they did not clear the forests or make residence too far inland. They said that the limit would be a days journey by foot from the coast. The Elves would set boundary stones and the two peoples could be good neighbours.
The tradition of the races formed about a generation later when the towns had grown and were starting to eye the boundaries. The people who had held discussions with the Elves had grown old and were no longer leading the people. The races were used to build support for the idea that the towns could expand a little further. Some more trees could be felled. Some more fences and shepherds huts could be built...
One year, after watching the outskirts of the human settlements creep past the line that had been drawn for them, a delegation from the Elves arrived in the each town the day before the races. They explained that they had heard that there was to be a display of athleticism and they wished to see it. They asked if everyone in the town was going to be running? Was the mayor running? The children? Grandparents?
They settled in for the night, then in the morning they followed the race, riding horses ahead of each leg and coolly observing the various support stops where runners would be provided with food and water kept waiting for them. As the leading participants passed the boundary stones and entered the forest, with spectators and the Mayor tailing along, more elves emerged from the trees, standing either side of the path and calling out encouragements. Elves in great number, fully armoured and armed.
The Elvish delegation maintained a polite face and congratulated the men and women who made it the furthest. They traveled back into town after the sun had set and made a show of presenting the best racers with awards. They gave a short speech - slightly different at each town, but all to the effect that the "one day's walk" limit had been intended as a guideline of where the boundary stones would be placed. The boundary applied to all the humans, whether they could travel a shorter or longer distance, whether supported or opposed.
The Elves could see that they'd made their point and with a final round of congratulations to all the racers, they returned to the forest.
Since that year, the inland boundaries of the Human settlement of the northern coast has been generally well kept, but the races continue. And each year the Elves come and celebrate the achievements of those who participate. Nowadays there aren't usually armoured and armed Elven spectators in the forest.