The latest set of Fortnite challenges are related to the Zero Point, the anomaly which lies in the dead centre of the map. This particular quest asks you to destroy crystal trees.
It sounds easy enough, but given the location of these trees, could prove to be a hassle.
Where to find crystal trees
Crystal trees can only be found near the Zero Point. You can find them all over the arid desert bordering the centre of the island. There are a few more clustered in the eastern part of the biome, closer to the Weeping Woods.
They are not very difficult to destroy — just farm them like you would trees and rocks. Funnily enough, they provide stone as a material, not wood!
However, given the nature of the location, there is a high likelihood of many players hotdropping at the start of a match. It might be worth coming back to the area later, or even playing in Team Rumble mode which will allow for respawns.