Blighttown Key

In Game Description

Key to Blighttown from the Depths of the
Undead Burg. Swallowed by the Gaping Dragon.

As its name suggests, Blighttown is a place
of great pestilence. Even the polluted
inhabitants of the Depths are aware of its
dangers, and built this mighty door in hopes
that they could remain safely separated.

Availability

Defeat the Gaping Dragon in the Depths

Opens

The large double doors near to where Domhnall of Zena sits in the lower level of depths that lead to Blighttown