Event spawns that happen in open spaces across the map in Epoch Mod. There is high value loot to be found at these events, including but not limited to: building supplies, weapons, explosives(chance to spawn).
This red dot on the map can indicate where a ferris wheel may have spawned. Look for a red dot that occurs in an open area. If the red dot is inside a building this likely indicates a dead trader and not a ferris wheel.
This is what a ferris wheel event looks like at a distance. (v0.3)