Great Lake

The Great Lake is a large lake that lies northern part of the Great Forest of Tob and the southern end of the Azerlisia Mountains.

Background
This enormous lake has a radius of approximately twenty kilometers, and was shaped like an inverted calabash or ladle. Its waters are fed by the Sighing River that flows between the southern tip of the Azerlisia Mountains and Great Forest of Tob.

The Lizard Man Heroes Arc
The Great Lake is the main setting for this arc, specifically the Wetlands, where the lizardmen reside. The Great Tomb of Nazarick plan to expand its power and turns its attentions to the demi-human tribes of the Great Lake. Wishing to convert the strong bodies of the lizardmen into powerful undead, Ainz sends out Cocytus to carry out the campaign.

After arriving at the southern part of Great Lake, Cocytus sends out a messenger to delivered the message to the lizardmen tribes. After delivering the message, instead of cowering in fear of the threat, it promotes the lizardmen tribes to unite to overcome the invasion. Led by Green Claw, the tribes unite under one banner and face the undead army. After eight days of preparing for battle the lizardmen successfully become one tribe, they managed to obliterate the first wave of the attack and later fend off the second.

Cocytus seeing that he is on the verge of defeat immediately sends out Iguva=41. Alas the lich though powerful also falls to the combined might of the tribal chiefs. As the last undead falls it leaves the lizardmen in triumph.

Layout
The lake is divided into two parts. The upper lake and the lower lake. The upper lake is relatively deep, hence large creatures gathered there while the lower lake was inhabited by smaller creatures.

Wetlands
Located at the southern end of the lower lake was a large region where the lake and the wetlands blended into each other. Several tribes of lizardmen lived here and made their villages over the muddy lands.

Trivia

 * Supposedly the Great Lake once froze over in the past.