Symbol of Peace - Altissa
First Available: Chapter 9
Other Requirements: N/A
Rewards: 1,000 EXP
This quest is found in Altissa during Chapter 9 and is accepted by passing by the two women gossiping in the picture above. There is no marker on your mini map or map prior to accepting this quest and all you have to do is get near the women to accept it.
For this quest you need to visit Lady Lunafreya's dress which is found in the southeastern portion of Altissa. The location won't be marked on your map so you're going to have to basically stumble into this area too. Use my map below for the exact location of the dress or listen to the residents of Altissa as you run through the city for directions.
Once you locate Lady Lunafreya's dress the quest will complete and you'll receive your reward.