The lore-based explanation behind this area: it’s called the Iron Keep, the home of the Alonne kingdom (namesake to the enemies you dispatch in the area). The whole land around the keep—including the keep itself—sank into the ground over time and eventually hit a lava well, flooding the surroundings with a different kind of moat.

The gameplay-based explanation for the area: it’s a bow-wielding sniper nightmare. Greatbows have a significant knockback capability and the drawbridges the span lava-filled ravines aren’t that wide. If you’re in the right spot, hitting the broad side of a player trying to cross a bridge with a greatbow will certainly knock them off the bridge and into the lava below, instantly killing them.

All of the players who were de-bridged from the video above seem to be wearing lighter variants of armor, as becoming a nimble glass cannon can trump increased tank-like defenses in most PvP situations, but I wonder if wearing heavier armor (such as Havel’s set) could offset the knockback enough to power through to the invader’s position. I wager it’d be worth experimenting with to find out.