Dark Souls 3: The Ringed City has a lot of new content, including armor and weapons. Below you will find brief descriptions for where to find each of the major new items.
Aquamarine Dagger
Dropped by the Headless Guard near the Old Hag upstairs from the Dreg Heap bonfire.
Herald Curved Greatsword
Located behind a Giant Knight in the toxic lake.
Ringed Knight Armor Set
Each item of the set is a low percentage chance drop off of Ringed Knights.
Ringed Knight Straight Sword
Located on top of a destroyed building near The Ringed City Streets bonfire.
Ruin Armor
Located under the ghostly archer squad in the Ringed City area. Follow the side path into the tomb area to find this set lying against a wall.
Splitleaf Greatsword
Purchased for 11,000 Souls from Old Hag near the Dreg Heap bonfire.

Embark on an inspiring mission of human connection beyond the UCA. Sam — with companions by his side — sets out on a new journey to save humanity from extinction. Join them as they traverse a world beset by otherworldly enemies, obstacles and a haunting question: should we have connected?