The Kahlenberg is a 484-metre wooded hill at the eastern end of the Vienna Woods (Wienerwald), overlooking the city, the Danube, and on a clear day the Carpathians. The view from the terrace is the classic city panorama: the Innere Stadt clustered around the Stephansdom spire, the river arcing through, and the Pannonian Plain stretching east.
A small church marks the spot where the army of Jan Sobieski paused before its descent during the 1683 Ottoman siege. The 38A bus from Heiligenstadt gets you there in around 25 minutes; from the top, marked trails descend through vineyards back to Grinzing for Heuriger wine.