How long is a drive from Tripoli to Sparti?
 

As I understand, it is not much of a highway, so trying to figure out the driving time.
And yes, I know that there isn't much of ancient Sparta in Sparti, but my daughter wants to see where it used to be - what a father can do, but drive on? :-)

Have to clarify:
I know that it is 58 km. But with all those bends to the right, curves to the left - is an hour feasible for somebody who has never done a mountain driving before or I should count 2 hours?
Thank you

It is actually a good highway, mostly two lanes. While it is mountainous and curvy it is a major route not a tiny secondary road in a remote area.
Just keep to the speed limit and keep alert for Greeks passing on blind curves, keep as far over to the right as you can and let faster cars pass and you will be fine. An hour is probably just about right for that trip.

Sparta is a bit thin on attractions. It has a very good olive museum and of course the wonderful Byzantine city of Mystras which is a great site just 5km out out Sparta. You should expect to spend 2 to 5 hours there.
Some pictures
http://travel.webshots.com/album/551988174qxbTNw


Where are you going after Sparta. You will find those awful switchback roads you are concerned about if you head directly west from Sparta to the coast. We averaged about 23 km per hour that day.
If you go straight south to Gythion you will find the ancient port city of Sparta. This is the port where Paris and Helen departed from. The road to Gythion is also quite good and not mountainous.

If you have time a night in Monemvassia is an inspiring destination. From the moment you enter the bullet scarred doors through the city walls you step into a 15th century city. Even better you can spend the night in a period room.
More pictures
http://travel.webshots.com/album/551987765EoLDkO
Have a great time

I would say about an hour, more if you pick a busy time like a Friday afternoon!
As Stanbr says, take the opportunity to visit Mystras while you are there.
If your next destination does take you west the road IS full of switchbacks & over mountains, but just allow plenty of time & enjoy it. It's a good road & one of the most spectacularly scenic routes in Greece.

I wish we had time to drive around: everybody is so excited about Peleponnese. This time however it's not more than to satisfy my daughter's unexpected historical curiosity, have a look where Sparta was and head back north to Nafplio, so I was wondering whether it's doable in one day: definitely doesn't make sense to rush on the unknown roads.
Thanks a lot for the info, really helpful.

Mystras truly is a "must see" on the Peloponesses ... it would be a shame to miss it. Even 2 hrs on site, would be a treat.

The mountainous road from Sparti to the east coast is slow, but beautiful.

Few years ago I drove south from Nafplio along the eastern coast. Turned inland (west) near Leonidio; visited the Elonas (sp?) monastery, literally carved into a steep mountainside; through village of Kosmas; contined south to Gythio, and eventually on to Monevasia.
The drive was a highlight of my trip.
But it did take around 8 hrs, what with all the stops.

Mystras was absolutely fascinating to us. Sparti... really was a nothing for us.

Here's the appropriate page from our trip report:
http://www.onelittleworld.com/greece_5.html