Cir X-1 is a famous neutron star X-ray binary that appears to give contradictory evidence as to its age and nature, mixing some spectacular properties from different classes of X-ray binary. We have attempted to constrain the nature of the source with a combination of archival X-ray observations and high-resolution spectra with AAT/IRIS2. In this talk I will describe why this source is important and present results from our investigation into this fascinating source.