The Observatories of Nerak

From publisher blurb:

The wizard pinpointed the origin of all the odd magical surges disturbing her experiments - they seem to be coming from a trio of ancient observatories. We thought they'd be abandoned but - to the contrary! The elves here seem quite eager for our help, though it's impossible to tell if they're more scared of the dragon plaguing the region... or the astronomers who inhabit the towers.

This is a system-agnostic dungeon designed to slot easily into whatever kind of campaign you might be running. Use it as an elven settlement, a random wilderness encounter, or the location of important information/items the party needs.