You can find the Red Forest Biome in the overworld

To enter the new dimension you need to:

1. You need to craft Red Iron.

1. Then smelt the Red Iron to get Melted Red Iron. This will be the igniter for the portal.

1. Then craft Soul Coal. This will be used like obsidian to make a portal shaped like the Nether Portal

1. In this dimension the water will cause Nausea and Weakness Effects. To avoid that you need to hold in your hand or offhand a Red Ring. You can craft it using Red Iron and Lapis Lazuli.

1. Then create a Nether - like shaped portal (ignite it with Melted Red Iron)

1. When killing a Red Pig or Red Ghast in the new biome or dimension you will be awarded with the Red Pig Eye. When eaten you get Jump Boost, Speed and Feather Falling.

Note: This dimension is very good for diamond mining. Diamonds can be found in any y level.