Crymson
CAGiversary!
Again I have not tried this out, but you are more than welcome to. This is ripped straight from the bungie.net forums so forgive the spelling errors of the dolt who wrote it.
"SANCTUARY: this jump is to get on top of the center ring room's roof
start by getting on top of one of the two bridges that leed to the center room. face the center room, to your right there is a water way. where this water way meets the wall of the center room there is metal box with its upper outside corner cut off. jump and STAND (not neel) on this box. once your on this you can either jump to the right or the left. BE SHURE TO JUMP LATE, turn in middair and crouchwalk to land on the roof."
source: http://www.bungie.net/Forums/posts.aspx?postID=3150314
EDIT: Just tried it out, extremely easy to perform and quite useful for capture the flag or assault. The hardest part is getting on the "metal box" to make the jump.
"SANCTUARY: this jump is to get on top of the center ring room's roof
start by getting on top of one of the two bridges that leed to the center room. face the center room, to your right there is a water way. where this water way meets the wall of the center room there is metal box with its upper outside corner cut off. jump and STAND (not neel) on this box. once your on this you can either jump to the right or the left. BE SHURE TO JUMP LATE, turn in middair and crouchwalk to land on the roof."
source: http://www.bungie.net/Forums/posts.aspx?postID=3150314
EDIT: Just tried it out, extremely easy to perform and quite useful for capture the flag or assault. The hardest part is getting on the "metal box" to make the jump.