Which area to unlock chests?

In which area should you unlock chests in hardmode, meaning which area has the most valuable weapon skins?

Gate of Fear.

Just little difficult to make a chest run in that area

Nightfall --> Realm of Torment --> Domain of Fear--> Chests found near Tyrian Titans

These chest have a chance of dropping inscribable Magmas Shields

And besides that? Areas you may need for vanq.?^^

lots of areas in Cantha have a chance at dropping weapons that still sell for a fair sum.

Echovald/Gothic/Ornate Shields in the forest, for that matter the rest of the rare Canthan shields although not all in the forest.

Also in Cantha the chance at nice Bo or Dragon Staffs that are still worth decent gold.

Although these things are valuable because it is very rare to get drops with nice reqs and mods so good luck if you choose to try