River of Flame (Act 4)Moving to Act 4, there aren't numerous waypoints throughout the region. That makes establishing farming spot preferred spots a bit more difficult D2R ladder items. Hence, most players simply go to River of Flame River of Flame as both a gold mine and the chance to test whether their characters have what it takes to weather some of the most difficult challenges.
River of Flame has clustered monsters and lava that only Barbarian equipped with Leap or a Sorceress with Teleport are able to use for their benefit. Additionally Hephasto, the Armor is always looking to kill players. Should they overcome these challenges and win, they'll be richly rewarded.
Chaos Sanctuary a.k.a. Diablo Run (Act 4)In the event that they don't get anything significant or interesting at the River of Flame, players will be able to proceed to the next large area, which is Diablo's mainhold, Chaos Sanctuary. The same goes for the Chaos Sanctuary, which houses several of the most powerful and generous enemies in the game.
If the monsters do not drop something interesting, then Diablo himself certainly will. It's good to know that Diablo isn't that difficult of a boss to dispatch buy d2r items. Diablo's attacks are easy to avoid and even an affordable Bonemancer build can take on him.