Pyramids

As of version of Atum 2.2.6 for Minecraft 1.16.5 there is a change in the way you can enter the hole. Now the entrance is a 2x2 unbreakable blocks as of the rest of the pyramid. To convert those 4 blocks into a double door that you can actually open you must put 1 Nebu torch on each Quandary block on the left and right side of the 2x2 blocks. They will glow, activate and converts the unbreakable blocks when you put the Nebu torch on them. Pyramids are huge structures that generates almost in every biome.

To get to the pyramid you must dig next to the pyramid until you find a small hole. The hole is mostly in the middle of one side. Then you must find your way to the boss room by going through maze full of traps. In Boss room you can summon Pharaoh by placing 4 royal torches around the sarcophagus on the carved limestone and right click to sarcophagus.

As of new Atum 2 version royal torches have been renamed to Nebu Torches

The original creator of this mod uploaded a video showing Bosses in Atum 2. You can watch it here