What audiences didn't expect is that Mordor and Mount Doom would be born this early in the series. However, those familiar with Lord of the Rings' extensive history would've been able to work out that this iconic location would be part of episode 6. Its official title – Udûn – is also the name of a barren valley situated in northwest Mordor, so it wouldn't have taken much for diehard Tolkien fans to make the connection.
Before its visually arresting effects could be added in post, The Rings of Power's chief creative team had to make sure that events preceding the eruption could lead to the mountain – that becomes Mount Doom – violently blowing its top. After all, such a move is only possible via the collision of its vast lava pit with water from Ostilith's deep reservoir.
"It was important to us to use real world locations," Ames reveals."The actual mountain itself is based on a real location. The cliff that Ostilith sits on is an actual location. We went to those areas and shot backgrounds using helicopters. We also landed in those areas and took photographs and plates. Even the water you see in the final sequence is real – it's just mixed in with some CGI elements to aid the flow of this massive deluge as it careens down the valley.