Dragon Age - Thedas

The Dead Trenches is an underground fortress, accessible via the Deep Roads. The area becomes accessible after traversing Ortan Thaig Bownammar, also known as the City of the Dead was once the headquarters of the Legion of the Dead. The fortress was reclaimed by the dwarves and lost again to the darkspawn so many times that even the Memories cannot track it. Eventually it was permanently lost in 9:13 Dragon only with great regret. It is now called the Dead Trenches. Paragon Caridin designed it long ago and it is considered one of the finest works of the dwarves.