Dwarven Tome of Urmon

This well-worn book is a journal written in Dethek, the dwarven tongue. It was found in Iarno Albrek's quarters in the Redbrand hideout below Tresendar Manor in Phandalin.
The yellowed, crisp pages are mostly in good condition, although age has claimed a few. The tome details the journeys and life of a dwarven adventurer and lore enthusiast named Urmon. Most of the content is written on a day to day basis, ranging from short, single day descriptions ("The Shining Serpent Inn's eel pie continues to disappoint") to longer ramblings of Urmon's interests and worldview. This book is dated to around 950 DR, or dalereckoning, over five centuries ago.
The owner of this journal seems to have dog-eared a number of select pages. These pages have passages circled and annotations in Common. Looking closely, the writer of the annotations is frustrated that the contents don't specifically say how to enter "W E C."
A few important entries detail the following:

• Clans of dwarves and gnomes made an agreement known as the Phandelver's Pact, by which they would share a rich mine in a wondrous cavern known as Wave Echo Cave. In addition to its mineral wealth, the mine contained great magical power. Human spellcasters allied themselves with the dwarves and gnomes to channel and bind that energy into a great forge, called the Forge of Spells, where magic items could be crafted. Times were good and the nearby human town of Phandalin prospered as well. But then disaster struck when orcs swept through the North and laid waste to all in their path.

• During this same period, a powerful force of orcs reinforced by evil mercenary wizards attacked Wave Echo Cave to seize its riches and magic treasures. Human wizards fought alongside their dwarf and gnome allies to defend the Forge of Spells, and the ensuing spell battle destroyed much of the cavern. Few survived the cave-ins and tremors, and the location of Wave Echo Cave was lost.

• There is record of a magic mace named Lightbringer that was commissioned by priests of Lathander, the god of dawn, from the mages working with the gnomes and dwarves of the Phandelver's Pact. The mace was lost when Wave Echo Cave and its mine vanished from history.

One notable annotation by Iarno Albrek is as follows:
"I wonder if the recent orc movements have been inspired by this history. Local rumors keep talking about a white dragon having pushed the orcs down from the mountains. What if the orcs are looking for the mine themselves?"