*NOTE* This is considered a bug and people have gotten banned for it cause their dumbasses grouped up in huge zergs. This is still in game and can be done, but don't do more than 5 people at a time so you don't get banned.

Map:  Iron Marshes
WP:  http://gw2.mmorpg-life.com/firewatch-encampment-waypoint/23059/
Event:  http://wiki.guildwars2.com/wiki/Defend_mortar_operators_from_Flame_Legion_as_they_set_up_mortars
Gold/H:  11.5G salvaging frayed garment, and opening medium ritual bags, then selling linen scrap, about 160 linen scrap per hour

*TIP*  Let NPCs die on the bridge before all mortars are constructed, and then flame legion spawns non-stop on both sides of the bridge, alternate killing at each end, with 3 players get 5 mobs per side.