I've figured it out. It's SkyWars. How do I know exactly? Well, that leads me to the image that c0w had posted. See, if you look closely at the upper center right, you will see a chest hidden behind a tree. Also, there are several islands floating around a large castle. Everybody knows that we have to battle each other to get to the castle with loads of items in order to be victorious. There is quite a large gap in the middle of the islands so that should be the amount of space you have to make your way towards the castle. That's all.