The biggest feature of the Mountain Pass in Baldur's Gate 3 is the Rosymorn Monastery, which the githyanki have claimed and converted into Crèche Y'llek. The crèches are places for githyanki to raise their children safe from enemies, since time doesn't pass in the Astral Plane they call home.
Baldur's Gate 3: Where to Find the Egg in the Githyanki Creche
The Society of Brilliance is on the hunt for a githyanki egg, which players can acquire without any fighting.