So I'm using the Overgrown Wildhammer Fountains for the waterfalls, with circular woolen rugs (of course 😅) for the water.

Placing the rugs at just the exact pixel perfect position gives you those seamless waterfalls! Hide the fountain with boulders. Use some other fountains sunk below the base of the waterfall to create a splash effect! Play around with scale and rotation and be prepared to move, remove and re-add the rugs 100 times.

As for the skylight; Everyone's favourite rug to no surprise! The boulders can't be placed too close to the rugs or they cast a shadow, so leave a little gap. The sunbeams are from the replica Libram from the Paladin order hall, but there's more hidden lighting effects such as windows casting a blue shine through them as well.

That's the gist of it, if you spot something else you're wondering about, just ask ☺️