There's a hidden waterfall cave located in the Emerald Stair region of Avowed that players can visit to get the Death Knight armor set & sabatons.

El Pailon del Diablo, aka the Devil's Cauldron, is a massive waterfall in Ecuador that you can get super close to. All you have to do is pony up $1.50, and climb a winding staircase right up to it.