The Agora was the central gathering place for all of Athens, where social and commercial dealings took place. Arguably, it's most important purpose was as the home base for all of the city-state's administrative, legal and political functions. Some of the most important, yet least acclaimed, buildings of ancient history and Classical Athens were located in the Agora.
The Tholos, a uniquely round structure similar in general appearance to the Mycenaean tholos tombs, was completed around 470 B.C. Also known as the Skias, it was the headquarters of the Prytaneis, or the Executive Committee of the Boule (the Athenian Senate). The Prytaneis was comprised of 50 men from each of the 10 Athenian tribes that rotated every 30 days. They ran the daily operations of the Senate. The Tholos building was used as their meeting place, a dining hall, and had sleeping areas to accommodate the necessary round-the-clock shifts of the committee members.
Near the Tholos was the New Bouleterion. This rectangular building, where the Boule met, was constructed near the end of the 5th century B.C. next to an older and less "contemporary" building that had served the same function. This large building accommodated the 500 member Athenian senate. The old Bouleterion building was given a new name, the Metroon, when the Senate moved to their new accommodations. The Metroon, used for archival storage even when the Boule met there, became a full-time library of important Athenian documents around 405 B.C. Those valuable records are unfortunately lost forever, as they were written on parchment and papyrus, which had a very limited shelf life, particularly in the arid Athens climate.
The Metroon also housed the cult of Rhea, who was known as the Mother of Zeus and some of the other Athenian gods. A cult statue was located inside the building.
Adjacent to the Metroon was the Monument of the Eponymous Heroes, which was a statuary monument that represented the 10 tribes of Athens. The names of each tribe were taken from 10 past Athenian heroes decided by the Oracle of Apollo during the time of Kleisthenes. Acting as not only a reminder to all Athenians of their ancestral roots, this monument also served as a public information station, where notices applicable to each tribe would have been posted, as well as any other general information important to the city as a whole.
A building similar in architecture to the painted Stoa, the Stoa Basileos was originally constructed in the 6th century B.C. After suffering greatly from the Persian attack on Athens in 480 B.C., it was reconstructed in the 5th century B.C. This stoa would have been home to the Archon Basileos, or the archon king. The archon king managed all religious aspects of the city-state, including Mysteries (religious festivals), sacrifices, and lawsuits pertaining to impious or "unholy" situations. Most notable about the Stoa Basileos was the limestone block located in front. This was known as the Oath Stone, where new magistrates would have taken their oaths of office.
No center of law and politics would be complete without a place to uphold and demonstrate the democracy Athens and its leaders were so proud of. And so, a large set of Lawcourts was located in the Athenian Agora. Located on the west side of the Agora, this complex would have been very large, in order to accommodate the constant litigation going on (both publicly and privately).
Athenian juries were not the typical 12 peers we know in our courts today. The smallest jury seated in the Athenian lawcourt was around 200 men, and a jury could have gotten as large as 2000 Athenian citizens.
Unfortunately, there is little archaeological evidence to pinpoint the exact location of the Athenian lawcourts. There is, however, evidence to suggest where they were located in the form of a stone box excavated containing bronze discs. According to ancient Greek historians, jury members would have used these discs in order to cast their guilty or not guilty votes during trials.
The wheels of Athenian democracy were churning feverishly in the Classical Agora, with accommodations for all vital factions of the new form of government, helping to blaze a trail for our own modern political and legal structure.