How to make a cave

Making a cave is almost as easy as making a hill or a simple hole.

• Open up sandbox and the map you want to make cave to.
• Make a hill or sth you want to make a cave into.
• Select the area of which the cave can reach like this: picture :)
• hover your mose over the area and press H
• Start scrolling forward until you have your cave :)
• If you want to make the cave go into ground too, then just press H to exit heightfield mode, hover your mouse over the ground press H again and scroll on until you have the desired result :)

Tutorial by Siimvuss.