How to get to the Lair Of Romulus in Campagna?
I can't find how to enter it, anyone help?
You've probably figured it out by now, but you have to climb onto the roof and drop down into the courtyard.
Yeah, I get that, but where abouts do you drop? I'm talking about the one in the ruins BTW (if there was any confusion) 
Sorry, I was thinking of a different one.
It's probably underground. That might be the one where you have to repair the nearby aqueducts in order to fill the lower area with water so that you can swim over to the entrance (and a treasure chest).
Interesting fact:
Before you fill that area with water, you can actually swim and dive under the wall and end up swimming around under the game world. You can see people walking above you and all the trees and buildings and such. I didn't explore very far when I discovered it because I didn't want to get stuck. You can get back by diving back under the wall.
Ah, that's it.
Okay, so i renovated the nearby aquaducts but it still hasn't worked :S
EDIT
Ah, it's okay. There was one i needed a viewpoint for. Thank's for your help 
u can also get up thare via climb leap but its tricky i got into that lair before i did the repairs on the aqueducts lolz
u can also get up thare via climb leap but its tricky i got into that lair before i did the repairs on the aqueducts lolz
Yeah, there's a way to just stand above the ledge, and Hold the Empty Hand button, until Ezio grabs onto this little lip. Then just move to inside the entrance, and from there you can Side Jump (he'll land on it with his feet IIRC) and get the treasure. However, the Lair won't open until you've renovated the aqueduct
relay O__o mine did XD
I dropped over the lip just to the right and above the entrance, let go, held grab on the way down, sidled around the corner until Ezio's left side was pointed at the archway entrance, then did a climb leap straight up, held left and held grab.
He swivelled 90% mid air, grabbed the bottom of the ledge the lair is on and I pulled myself up.
I hadn't repaired the aqueduct and was able to get inside to do the lair. Only needed the climbing gloves.
When i replayed the game this stumped me for a while aswell. On my first playthrough i think i repaired all the acquiducts before doing any of the lairs so i didn't realize the water level was so low there.
I dropped over the lip just to the right and above the entrance, let go, held grab on the way down, sidled around the corner until Ezio's left side was pointed at the archway entrance, then did a climb leap straight up, held left and held grab. He swivelled 90% mid air, grabbed the bottom of the ledge the lair is on and I pulled myself up.
That was a really clear explanation, morninglord. Following these instructions was as easy as watching a video.
Climb Leap + Catch Ledge Left works fine but you can substitute a Jump Left like DAZ suggested. That way you don't even need the Climb Leap ability. I'm making a video of this lair and will demonstrate both the jump and the aqueduct repair methods.