Schloss Seggau perches on a dramatic ridge above Leibnitz, visible from across the valley and well worth the climb. The complex is large and layered, with medieval fortifications, baroque chapels, and a Roman lapidarium built up over more than a thousand years of continuous use. Today it functions as a retreat and conference centre run by the Diocese of Graz-Seckau, but visitors are welcome to explore the grounds and many of the historic rooms.
The views from the terrace are the best in the region — rolling vineyards stretching toward Slovenia in the south, the Sulm valley below, and the alpine foothills to the north. The on-site winery produces South Styrian Sauvignon Blanc and Welschriesling, and there is a restaurant and wine shop where you can taste the estate's wines alongside simple Austrian food. An easy walking path leads up from Leibnitz through the vineyards in about forty minutes.