Maibachl is Villach's little natural surprise: warm water that emerges in the woods near Warmbad after snowmelt or periods of heavy rain. When it is flowing, shallow pools form among the trees and locals come for a free soak in water that feels faintly illicit precisely because it is so informal.
The catch is that Maibachl is seasonal and unpredictable. Do not count on it during dry spells, and treat the area gently if you find water running. Bring a towel, keep expectations simple, and remember that the charm is the temporary nature of the place, not spa-style facilities.