Admont Abbey

From the Wikipedia page on Admont Abbey

Admont Abbey (Stift Admont) is a foundation of the Benedictines on the River Enns in the town of Admont in Austria and is the oldest remaining monastery in Styria. It contains the largest monastic library in the world and a long-established scientific collection, and is known for its Baroque architecture and collections of art and manuscripts.

The website, in German and English, is