Lavrion is a seaside little place and can be, when its calm, kind of pleasant.
Lavrion alternates between sleepy and mayhem depending on the ferry schedules, which in turn depend upon the time of year.
In Greece, seaside towns like Lavrion usually means traffic congestion and only one vehicle lane each way. Add to that the need, and right, of every one to park and then to double park, and when it picks up, like Sunday afternoon, when everyone is returning to Athens - well, it can become dowwnright frustrating.
Seaside towns like Lavrion dont have the room to planned wide boulevards and clinging as they are, to the shallow slopes of submerged mountain tops makes for a proscribed but often bumper to bumper path.
Cape Sounion is just south of Lavrion which is 54 km from Athens. The whole drive around Attika's coast is pleasant including passing through Lavrion.
For more information about Lavrion and ports including maps, bus routes and ferry schedules please visit my Ferry info Greece at a glance section!
There is a lot of truth to relieving Piraeus's congestion by using Lavrion and Rafina but that will just cause congestion elsewhere on Attika's roads.
In ancient times and not so ancient, there was a silver mine in Lavrion which was a source of great wealth to the Athenians.
Among others things you may have seen are the famous Athenian Owl headed coins. There are some minor ruins but the big attraction should be near by Sounion's Temple of Poseidon and the beach.