In Lynn Nottage's Ruined, identify a significant symbol.

I would say that Mama Nadi's brothel is a significant
symbol in the drama.  The conventional view of a brothel is a place of dehumanization,
of significant belittling and an arena where hopelessness reigns.  Nottage inverts this
a bit and makes the brothel a significant symbol of hope for the women who stay there. 
In doing so, Mama ends up providing shelter to the women.  If Mama's brothel is not
there, there is a very good chance that the women will be enslaved or raped by the army
and the ravaging of civil war will become reality for the women.  The brothel is
symbolic of how the women might have a chance to redeem their future in a setting where
redemption is challenging to find.  It is in this where I think that the brothel becomes
significant.  Consider that Christian brings Sophie to the brothel because she is
"ruined."  It becomes symbolically important to note that women who are ruined are
brought to the brothel, traditionally a place where women go to become ruined.  In this,
Nottage makes an important symbol where redemption becomes possible in a setting where
so little can be redeemed.