I've been mapping the "camp" or hillfort for the last 12 month, using a base map from Hogg and also using Google satellite imagery and other published photos. A lot is visible just now, following extensive burning.
This is a very spectacular and technically sophisticated hillfort, with features similar to Norman motte and bailey castles. The fort is on a rocky ridge, with a 'village" inside a pronounced defensive embankment at the NE end (the lee side of the mountain) and three connected enclosures or baileys at the SW end. On the SE face of the mountain natural cliffs and scree slopes are used as defences -- and on the NW side substantial defensive embankments have been built. The rocky summits of the mountain are the "motte" -- no doubt used as a last defensive position in case the defences were breached.
The defensive embankments have been slighted -- when and why?
Visited 2nd May 2004: We parked north of Bedd Morris (approximately SN039367) and after a picnic lunch headed of to find the hillfort. The route I'd chosen was based purely on keeping the gaps between the contour lines as small as possible (with Alfie on my back I had a good excuse). It took about an hour to get to the fort, but that was at William's walking speed.
The fort is an impressive but disorientating jumble of rock. We approached when the cloud was low, so it wasn't possible to see the summit of the hill even from close up. There is an entrance to the fort, which would have been the best place to get into it, but we only figured this out once we'd clambered over the ramparts at the south end. The terrain inside the fort is tricky, and not recommended for anyone with limited mobility. It was fun to explore, but the drop to the east was significant enough to worry me.
There's at least one discernable rampart within the boundary of the fort, and something that looks a lot like a hut circle. Outside the boundaries of the fort, especially to the east, are a number of structures that represent huts and areas of cultivation contemporary with the fort. As with everything at Carn Ingli, it's tricky to figure out what's what.