Denladian

The eastern island of Kleet, with groves abundant. East by 345 blocks, withholding the mountain that guards the groves, the second tallest in all the land, the mountain of Ephialtes. With Ephialtes comes its sacred grove, being told upon the name of its guard. The guard does not forget its smaller island of Fiincea, beyond it the Vast Unknown. This project was made with World Painter.

World Painter is a map maker where it is not randomly generated, but you design it and can export it to Minecraft.
World Painter, available for Linux, (deb and rpm) Mac OS X,and Windows. (32-bit and 64-bit)
https://www.worldpainter.net/

Two brush packs were used in the making of Kleet.
Jeracraft 6 brushes:
https://www.planetminecraft.com/project/six-epic-world-painter-custom-brushes/

Efcio 25 brushes:
https://www.planetminecraft.com/project/ecfio---25-worldpainter-custom-brushes---by-tylertimoj/