The Ayleids who fled to Valenwood after the Slave Rebellion were mostly those who worshiped the Daedric Princes, which was outlawed under Empress Alessia. The Slave Queen melded the Aedra worshiped by her human and remaining Elven subjects to create the Eight Divines.
Located in a central southern Grahtwood, the Ayleid ruins of Ne Salas is accessed by a footpath off the main road just west of Gray Mire Wayshrine. This delve is not a suitable location to farm crafting materials. The circular nature of the ruin make for a quick in / out for the skyshard and the delve achievement, but that’s about it.
In the world of Tamriel, its very existence is a closely guarded secret. The entrance to this covert city lies hidden in a secret underground vault, and its location is known to only a select few beyond Sotha Sil’s inner circle.
Once you have access to the Clockwork City of The Elder Scrolls Online: Tamriel Unlimited Divayth Fyr will offer you a quest in Mournhold or at the Clockwork City Wayshrine.
If you have a supply of recipes and ingredients, you can level provisioning in less that an hour. This tome suggests recommendations on leveling recipes, their ingredients, and links to sources of ingredients.