Blazing Fortress

The  is a location that resembles a nether fortress.

Location
The Blazing Fortress can be accessed after the player has attained Combat Level V by using a launch pad found near the top of Spider's Den, which you will have to get up first. This will take the player to a different sub-server containing the Blazing Fortress.

Features
Inside the fortress itself, there is Nether Wart, Blazes, and Wither Skeletons. At nighttime, Ghasts will spawn very high in the sky. During certain times, a giant Magma Cube Boss spawns which has a chance to drop the epic or legendary variant of the Magma Cube pet to those who dealt the most damage to it.

Outside of the fortress, there is a mine full of Glowstone, Netherrack, and Quartz, along with more blazes and Zombie Pigmen.

You have to come here for the fourth quest of the Romero and Juliette questline,

Romero can be found here. You must bring him one enchanted red mushroom block to do the quest.

Trivia

 * There's a flower pot located at which serves as a hint to players of a Fairy Soul below.
 * Another flower pot next to a Fairy Soul at -303, 107, -691 (via a tunnel starting at -301, 107, -704).
 * The Blazing Fortress is actually a Desert Biome.
 * While being a Desert Biome, it has a layer of snow on the top of the castle if it was viewed from the spider's den.