Unknown (Highvale elves)
Quel'Danil Lodge is a high elven outpost situated in the Hinterlands, being near Aerie Peak. It is the larger of the two major concentrations of high elves in Lordaeron and is one of the very last high elven settlements.
World of Warcraft
The lodge was used as a center of communication for the high elves of the Hinterlands. Their ambassadors were working to establish relationships with other races, with whom they shared their knowledge of the Witherbark trolls that inhabit the area in the southern Hinterlands.
After the Third War, the high elves of Quel'Danil struck an alliance with the Wildhammer dwarves, much to the ire of their common enemy, the Revantusk trolls. Otho Moji'ko of the Revantusk Tribe instructs Horde adventurers to slaughter as many Highvale elves as possible. After freeing the Witherbark troll Rin'ji and being pointed to an ancient tablet as reward, Horde adventurers delivered it to Oran Snakewrithe, a well known scholar on matters concerning Rin'ji's kind. She enlisted the same adventurers to burn documents that recorded the Highvale elves' communications with the other races and other information. However, Oran's and Otho's actions were unsuccessful, as the Highvale elves still retained the documents, which also included deaths, births and seasons.
As part of the Forsaken offensive in all the continent, the lodge came under attack. With the help of adventurers, the Highvale high elves and the draenei settlers were able to repel the invaders. The Highvale documents were also retrieved from the chaos by Alliance adventurers and safely delivered to Anchorite Traska.
The high elves that live in the lodge are referred as "Highvale" elves. This could mean that Quel'Danil means "High Vale", given that quel means "high" in Thalassian. After the loss of the Sunwell, the Quel'Danil elves decided to stop practicing magic altogether. Named quel'dorei inhabitants are Voldana and Ravic. Jalinde Summerdrake is assumed to be one of its leaders.
While the high elven race, for the most part, lost access to dragonhawk mounts with the split from Silvermoon City, Quel'Danil Lodge apparently has managed to maintain their own supply of dragonhawks.
Led by Ambassador Rualeth, quite a few young draenei (Tracker Yoro among them) settled in Quel'Danil to train in the ways of the Light and enjoy the peaceful beauty of the land. They are under the charge of Anchorite Traska.
While Quel'Danil Lodge has a kaldorei-like wooden architecture in-game, the mangas depict it with traditional quel'dorei/sin'dorei architecture.
In the RPG
Quel'Danil Lodge is a high elven hunter's lodge located in the Hinterlands, near Aerie Peak. Saldor Shallowbrook, an aged, placid high elf, oversees it. A connection between the elves and the Wildhammer dwarves formed, probably due to something about nature and wildness. Several high elves live in Aerie Peak and maintain good relations with the dwarves. In Thalassian Quel'Danil means "High Peak".
It acts as an embassy of sorts to continue the remaining high elves' diplomatic relations with other races.