[Lady-Loki]

I have found chests in places so open that there were other people all around it and apparently did not pay attention since many people expect them to be hidden, but then again, I have found chests in remote areas that I randomly went to and thought that it was kinda hidden and may have been there for a while. One example of out in the open was a chest sitting just steps off the dirt path in Forest of Tides where the Fire Mushrooms are - just sitting in the grass, and people closer to it than I was just going about life - two having a conversation, one shroomed (maybe afk) and one killing Fire Mushrooms).

As for ores, copper ore in Echo Cave accessed from Forest of Tides, Sand Beach & Sea of Greed. Silver ore in Windy Cave accessed through Moonlight Tomb & Goblin Camp (not sure if there is a third entrance). And Gold ore from Golden Cave accessed in Uruga.

Depending on what level you are you may or may not have to fight mobs to get to any cave. Needless to say, the higher your character level the easier any of them are.