Villach (Villaco, Beljak) is a great town for staying there for a day or two while traveling from northern to southern Europe (and vice versa). You can find here some good and not expensive hotels, as well as nice restaurants. The town's center is also worth visiting.
A good parking lot is located at the Moritschstrasse (GPS: 46.611921, 13.847683). The parking lot is quite huge, and - what's important - it is very close to the town center. So we leave the car there and then we walk about 200 meters the Moritschstrasse and 10-Oktober Strasse towards the Main Market square.
Before we get to the Main Market square, on the left we pass the St. Jakob church (A; GPS: 46.6132261, 13.8452711) - the main church in Villach, located right at the top of the Hauptplatz. The interior of this church is pretty interesting, with a notable pulpit. This late gothic church has also a very peculiar ceiling.
It's of course good to stroll through the main market square (B; GPS: 46.613360, 13.846147). There is interesting Trinity Column in the square, consisting of a box-like base with high pillar and figures of Holy Trinity. The column was probably created by Franz Bettini. You can also see some interesting town houses with nice decoration, for example the Hotel Post built in 1525.
The Main Market goes smoothly into the Bahnhofstrasse, which as the bridge leads through the Drava river. You can walk to the other side of the river and watch the old town from this perspective. Then you can again stroll other streets of old town, and walk towards the parking lot. Don't forget to visit a restaurant or pizzeria where you can have a tasty meal. There are many such places in the center of Villach; we visited a nice restaurant/bakery called "Konditorei und Restaurant Rainer" at Oberer Kirchenplatz 5 (C; GPS: 46.61287, 13.84495) and we were very pleased.