Mons Letalis stands for "lethal mountain" and is named so for a reason. The harsh climate of Marus Seru extends up to this very high mountain range, where more powerful monsters have come to live. Also within the zone are the remains of an ancient teleporter of Combine design, its use lost in history as it is now mostly destroyed.
The terrain is a constant danger, as you are nearly continuously taking falling damage.
This area also has many areas where creatures, usually ShikNars, will hatch underfoot while you are walking near them. This makes casual travel through the zone dangerous as well.
Travelling To and From Mons Letalis
The entrance to Marus Seru is located at -1400, -650.
The entrance to The Grey is located at 1400, 0.
Nostalgia from 1999-2003 EQ Atlas Web Site