Ravines

Ravines are tall, long cracks of air, about 5-20 blocks in height. The width is barely a few blocks, usually no more than 5, sometimes making ravines hard to navigate from below. Ravines can have small ledges along the top, which are possible to travel along. Ravines can be found at any level, and also scarcely appear on the world surface, forming canyons. Such canyons do, from time to time, appear underwater where safe entry is possible. They can go very deep underground, sometimes spawning Slimes or even exposing Diamond Ore.

Ravines can connect to caves, dungeons, abandoned mines, and any other generated structures. Due to the large surface area of their walls, may also have water/lava flowing down them (either from a spring or an underground lake of the lava/water).