Got to have watchtowers for those pesky rock climbing mongolian assassins. A nice smooth brick surface slows them down and slips them a bit like heavy beatles clamoring up glass. /s
It's a few hundred years later, after the Hittites have disappeared, but Assurnasirpal II claims to have scaled a mountain peak "like the point of an iron dagger" to slaughter everyone inside the fortress at the top. Twice.