Lac Eternel

Lac Eternel referred to an abandoned fort and accompanying settlement located in the heart of the River Valley, New York.

Sometime during the mid-18th century, it had been repurposed into a gang headquarters for the Colonial Assassins, through which they exercised their influence in the region. Having defected from the Brotherhood, the Templar Shay Cormac later captured the fort for the British after destroying the poison gas reserves and killing the gang leader.

Trivia

 * Lac Eternel is French for "endless lake".

Reference
Assassin's Creed: Rogue