The Castle Green was landscaped in the late eighteenth century by Capability Brown, but the park itself was laid out from 1873 on by Andrew Pettigrew, head gardener to the 3rd Marquess.

The park is situated along the east bank of the River Taff and adjoining Cardiff Castle, and offers a combination of arboretum, flower gardens and recreation grounds.

Sophia Gardens is home to the Glamorgan County Cricket Ground, where test matches are played, and to the Sport Wales National Centre.

An ironwork sundial, originally placed in the park in 1990 after a Festival of Iron event, was removed in 2006 and replaced by a small, round formal garden to honour Stuttgart (Cardiff's German twin town).

Its origins go back to medieval times when it was a millstream, constructed to feed the Lord's Mill, situated below the western walls of Cardiff Castle.