Cave systems that you can explore. They could even act as "shortcuts" between areas, allowing you to avoid hilly/forested terrain if you know where you're going; i.e. a cave tunnel that goes straight from somewhere around spawn to just past the monolith or somewhere on the side of the mountain. Could even contain hats.
#Caves
distant tundra
dawn beacon
Sninecraft yes pls
floral snow
need a snecret tunnel through the mountain. or make a sewer that connects from the inside of the well to so somewhere else
foggy fog
bumping top posts
limpid pollen
caves are a really fun/cool idea and there's so many different cave ideas peopl could have