Why should the landmasses form a circle here?

Why have they stuck 'Greenland' in it?
What even is 'Greenland'?

Strange world. Yes, it really is just level and non-moving (not a planet in space).

This raises a few questions.
什么这里的陆地会形成一个圆圈? 文
他们为什么要把"格陵兰"加进去?"格陵兰"到底是什么?
真是个奇特的世界。没错，它确实只是平坦且静止的(并非太空中的行星).
这引发了一些问题。