You are Socrates.

This is your first appearance in a court of law at age 70.

This is your opportunity to refute the charges against you.

You Socrates will defend yourself "in the same language which it has been my habit to use, both around the trading stalls of the market place (where many of you have heard me) and elsewhere…" (17c).

You are referrring here to the Agora, the large open area in the heart of ancient Athens where people came to conduct business or visit temples or relax and engage in more casual interactions in the many open areas. (Plato mentions the Agora as a frequent haunt for Socrates in many dialogues.)

Acknowledgement: http://lilt.ilstu.edu/drjclassics/texts/Plato/Socrates.shtm