Conderton Camp was formerly known as Danes Camp, only changing its name in the last few decades. It certainly wasn't built by the Danes though; it dates from the middle Iron Age.
I haven't been able to find any suggestion as to why it was called Danes Camp, but it occurs to me that the site is quite close to Deerhurst, where a treaty was signed in 1016 between the Saxon King Edmund Ironside and the Danish King Cnut (which handed over most of England to the Danes). It says in the Anglo-Saxon Chronicle that Cnut had his army with him, so perhaps they made use of Conderton Camp and this association got entrenched in local tradition. Well, they had to sleep somewhere and this ready-made hillside camp a few miles up the road was probably as good a place as any.
The Camp was excavated in 1958-59 by Nicholas Thomas, although the report of his findings wasn't published until 2005. It's well worth a read but here is a very concise summary:
The hillfort sits on a spur on the southern side of Bredon Hill, on a sloping site. The original fort was an oval enclosure with a gateway at each end (north and south). At some point the southern rampart was drawn up the hill a short way, forming the two-part camp we see today, though it appears that the lower section was not inhabited. The hillside on the east side of the camp (outside the ramparts) shows some distinctive ridges from ancient cultivation which are thought to pre-date the fort itself. Below the southern gate is a very rich area of springs which provided a plentiful supply of water.
The northern gateway was originally built as a simple gap in the rampart, probably with timber gates set into it. At some stage it was extended with an inturned entrance (still visible today). Later still, a drystone wall was built across it, blocking it off completely. During the building of the inturned entrance, a beautifully decorated weaver's comb (carved from a cattle rib) was placed under its foundations, presumably as some kind of ritual act.
The main inhabited enclosure was found to have contained about ten circular houses, though possibly not all existing at the same time as their foundations overlapped. One of the houses was excavated and its drystone wall foundations had survived remarkably well. Enough information was gleaned from this to allow a full-size speculative reconstruction of the house (now destroyed, but there are still photos of it). The camp was quite tidily organised into two parts, with housing on the east side and lots of storage pits (about 80 or 90) on the west side.
Among the curiosities found during excavation were three sheep burials, under the foundations of houses. The skeletons were almost complete, but very jumbled, and with some small bones missing. They are thought to have been buried like this for some ritual purpose. Other than that, the main find was an iron fire-poker.
The evidence suggests that the fort was eventually abandoned and allowed to decay naturally, rather than being subject to any violent attack - which is known to have happened at the slightly later Kemerton Camp hillfort on the other side of the hill.
For full information, see "Conderton Camp: a small middle Iron Age hillfort on Bredon Hill" by Nicholas Thomas (published by the Council for British Archaeology).
Dr. Treadway Russell Nash - "Collections for the History of Worcestershire" (1781):
"On Conderton Hill is a small oval camp, one hundred and sixty-five yards long, and seventy-one yards wide: tradition, which is better than conjecture*, supposes it to be Danish. Some few Roman coins have been found in the fields."
*Although presumably facts are better still than tradtion?