Kostolná-Záriečie (hu| Vágegyháza-Alsózáros) is a village and municipality in Trenčín District in the Trenčín Region of north-western Slovakia.
In historical records the village was first mentioned in 1318.
The municipality lies at an altitude of 206 metres and covers an area of 3.666 km2. It has a population of about 645 people.
The records for genealogical research are available at the state archive "Statny Archiv in Bratislava, Slovakia"