By far the largest forest in the known world, the Sea of Trees stretched over nearly a fifth of the Head of the Greatwyrm's landmass. Technically claimed by the Elthysi Sovereign, the Sea was in truth too vast and dangerous for the Mortalkind to chart or own. Despite efforts from Common League scholars, much of the Sea remained untamed and unknown.
Filled with all manner of Monstrositys and Abberations, the Sea of Trees contained Portals within its woods that led directly to other planes. The Elthysi Sovereign was concerned with fighting these monsters that entered its territory, but other groups also quelled evil within the trees. The Astralwood Enclave and the Elven bastion of Xilvalur watched the Sea from within its borders, fighting battles unknown by Somnum's great powers.
Many cultures in southern Commona believed that the Sea of Trees was an unstoppable tide of nature, a symbol of the rage of Elteos. These religions typically referred to the Sea as the "Wildweald", and believed that mountain ranges such as the Wealdshield and the Emberpeaks were placed as walls against the forest for protection.