Second to Vienna, the largest city in Austria is Graz. The city is made up of a blanket of red brick roofs, broken up with newer modern buildings that have recently been built in the city. A main landmark is the Kunsthaus, sitting next to the River Mur, it's a modern art museum. There is also the Murinsel which is a unique floating island on the river itself.
If you're hiring a car from Graz Airport, you can get directly into the city in about 20 minutes. There's plenty to explore in the surrounding areas too, but given the beautiful architecture and UNESCO sites on your doorstep, you'll be spoilt for choice.
The Old Town is a particular highlight of Graz, with a list of sights to see while you're in the city. The Grazer Schloßberg is the fortress of the city, with the hill leading up to it a sight in itself with the trees and winding stairs to access it. Just outside the Old Town is Schloss Eggenberg, this is amongst the list of world heritage sites, the palace has a beautiful façade with guided tours of the interior available to learn about the history. By hiring a car from Graz Airport, you can head out of the city centre to Lurgrotte. This extensive cave system lets you explore this natural wonder with the assistance of an expert guide to give you all the facts.