Once upon a time there was a place where Feywild was touching the Material plane. A place of unheard beauty, that inspired and attracted all kinds of beings in the area and even further. No one knows if the place was actually a part of one of those planes or both of them at the same time as creatures could go from one to the other without any disturbance.
After the Spellplague, the connection between the two planes was almost completely broken and it now manifests in the material plane mostly in a descriptive manner through lovely colourful nature and a faint aura of fey magic in the morning mists. That place is now called The Waterfall of Sparks as each single tiniest drop that escapes the tall falling stream of water shines with fairy lights and goes a bit up in a whirl before falling down with others. Often an observer could see few rainbows forming around the waterfall and several small fey creatures playing in the sparks.
Every few hundred years when an unknown fey calendar cycle completes, the connection becomes strong enough to open the Fey Crossing between the worlds which attracts beings of various intentions. For that reason powerful fey have placed two guardians in the material plane. Two fey creatures, born on the same day of the same mother, two sisters bound to the area below the waterfall to protect the magic of it and the river that follows, to guard the beauty of the forest around it and the delicate fey biome that has remained.
As time went by, the place has grown in significance among beings of Material plane. Several settlements have been built around and many wars were fought to gain exclusive control over the area. In those wars one of the sisters fell to the corruption of mortal world and desired the place for herself all of which turned into a disastrous battle among Fey, including the very powerful ones that descended from the Feywild. Battle was won by the good Fey and the evil sister, who became a powerful hag in the meantime, was exiled, never to return to the area.
Since then, the good sister, now a powerful Willow Dryad has managed to keep the peace, defending it from attacks, and presently she is an authority of the area that people and other intelligent beings in the area visit seeking advice, wisdom or a blessing. Most frequent among visitors were the citizens of an elven town nearby and a human/dwarven city down the river near the mountains. Other settlements in the area include few orc tribe camps, and a cave complex in the mountains populated by kobolds.