When Aurora brought up wanting ideas for build contest, I proposed a raid build. There is so much that can be done with raids... I play on another server where we use the nivex plugin and there are 5 tiers. Easy, Medium, Hard, Expert, Nightmare. 50+ different raids that are all randomly spawned around the map. That plugin is amazing. One of the absolute best features is that it locks it to the player/team who damages it first.
Adding to this. With the sheer amount of people who play, Nivex may not be the answer honestly as cool as it. Not sure how all the settings work exactly but it looks for flat surfaces. Just don't know how many spots it will have with all the player builds. And frankly, if you make them to good, just gonna go back to people camping/hoarding them.