Sparta

Geographical Locations of sparta:

Southern half of the peloponnese, this consists of Laconia and Messenia.

Sparta was said to be situated by the river Eurotas,  which flows through Laconia.

There was no actual Defensive wall or systems like many other greek cities did have, they relied solely on nature.

• They had a river valley
• They had rocky mountains
• They had a great reputation of being the best foot soldiers

The conquest of Messenia was when the spartans invaded messenia and Laconia.

The laconians were reduced to servility. The messenians were reduced to the status of "Helots", who were the slaves.

I'm guessing the Laconians were reduced to the perioikoi, who were basically the craftsmen and the poor ones were farmers on the left over land in sparta.

There was much limitations on Spartan evidence. They didn't leave much behind as it was lost in the Dark ages. However there were three main Ancient Historians that wrote about them:

Aristophanes, a comic playwright in Ancient Athens. That information is definately hindered as there was a battle between Sparta and Athens during his era and since he was a comic playwright, he would have probably mocked them.