I think for an event a Stairway to Heaven would be good, Really it is just stacking tons of tables chairs and stuff all the way to the top of the sky, and if you add traps like hunter freezing traps and maybe even a few monsters and first one to the top wins. To give an idea of these unless you have seen things like it on youtube i can use some screenshots with photoshop to show you what it would look like I hope you can use this for an event.

or travel from gm island by swimming.. farthest to reach land wins xD

Spurtle does have a point. I have seen these made before on other private servers, its like a "jumping" contest.

Basically the staff creates some sort of jumping thing made out of boxes with gaps. Make it pretty high with some hard jumps. First one to the top wins.

It can be fun, but gets boring fast. As well as it takes time to create as well.

I agree 68charger that is why i urge people to add things that could make it more fun, also if it is possible to make things like it, sort of trip wire things thatm could trigger AoE spells around u or things like freeze trap or entangling roots. Anyway its the peoples and GM's choice but i find stairway events fun