Unknown Book, Vol. II

It's one of the unique Unknown Books found in

The content of this book is written is the ancient Falmer language, however a translated copy can be obtained if it's sold to Urag gro-Shub in the College of Winterhold.

It relates to the ancient war in the Merathic Era between the Nords and the Snow Elves after the Night of Tears. The journal can be dated to some time around the Battle of the Moesring.

Location
Forgotten Vale Overlook - First, acquire the Emerald Paragon and activate it at the Paragon Platform to get to the Forgotten Vale Overlook. Once inside, follow the river north staying to the right side. Before the waterfall there will be a chest, some weapons, and Unknown Book, Vol. II.

Alternatively, reach the balcony of the Inner Sanctum and, using Become Ethereal, jump off the balcony onto the Forgotten Vale Overlook.

Content
Mirtil Angoth Journal