What would be a great idea for a fantasy world

I just saw two really interesting things on TikTok that i think would be great for a fantasy world, first was a rare biome called tropical fjord in Golfo Dulce in Costa Rica. fjord are most prevalent in places like Scandinavia so there's quite few tropical ones, i believe there's only 4 in the world.

The second thing I saw is the homes of the Hakka people of china, they built massive circular home called Tulou. They were created for self defense originally and they look really awesome, i love circular structures.