This modpack is mainly focused around space, dinosaurs, dragons and dimensions. You can find castles and towers upon exploration, and many types of dimensions. While you're exploring try to tame dinosaurs for a more efficient way of exploring. Make sure to look at recipes on how to create things, for example, building a rocket.

If you want to learn how to create portals, here are links for all the dimensions. (May contain spoilers)

Twilight Forest - hexxit.fandom.com/wiki/Twilight_Forest_Portal#:~:text=To%20create%20the%20portal%20you,it%20into%20a%202x2%20portal.

Atum 2 - www.minecraft-guides.com/mod/atum-2/

The Erebus - the-erebus.fandom.com/wiki/Travelling_to_the_Erebus

The Aether - aether.fandom.com/wiki/Aether_Portal_(structure)#:~:text=Aether%20Portals%20were%20made%20by,the%20opposite%20of%20Nether%20Portals.

Side note - You can find Dimensional Doors throughout your world.

Modpack includes:

Optifine!

Additional Lanterns
AppleSkin
Aquaculture 2
Atomic Science
AtomicStryker's Battle Towers
Atum 2: Return to the Sands
AutoRegLib
Backpacks
Better Animals Plus
BetterFps
Biomes O' Plenty
Castle Dungeons
Chunk-Pregenerator
Clumps
Collective
ConnectedTexturesMod
Coal 2 Charcoal
Cooking for Blockheads
Cosmetic Armor Reworked
Dynamic Surroundings
DimensionalDoors
Enchantment Descriptions
ExtraPlanets

Extreme Reactors
Falcon's Single Person Sleep
Fast Leaf Decay
FastFurnace
FastWorkbench
ForgeEndertech
Fossils and Archeology: Revival
Galacticraft Legacy
GraveStone MoD
ICBM - Classic

Ice and Fire: Dragons

Industrial Craft
Iron Age Furniture
Iron Chests
Iron Backpacks
JourneyMap
Just Enough Items (JEI)
Large Ore Deposits
LLibrary
Mantle
Medieval Craft
MJRLegends Lib
Mob Spawning Plus
Mowzies's Mobs
Neat
OreLib
Patchouli
Pirates
Placebo
Portable Crafting Table
Prehistoric Spawns
Quark
Rough Mobs 2
Spartan Shields
Spartan Weaponry
SuperMartijn642's Core lib
TenshiLib
The Aether
The Erebus
The Twilight Forest
Tree Harvester
Waystones
Tinkers Construct

ZeroCore 2

GBTB stands for Golden Bond Toilet Bowl