There are numerous gardens all around the castle complex. Some of them are directly associated with the castle, others belong to some of the ‘palaces’ which lie underneath the castle hill.
Yesterday, I stumbled on 'Zahrady Pod Pražskym Hradem' (which translates to 'Palace Gardens under Prague Castle'). These started out as a set of individual gardens but have now been merged into a single attraction. The original gardens, the Ledeburg, Small and Large Pálffy, Kolovrat and Small Fürstenburg gardens, and are situated on the southern slopes of the castle. Originally the site was covered in vineyards. For a full description of each of the component gardens, let me refer you to this site.
These are Prague's very own ‘hanging gardens’ which literally hang off the slopes underneath Prague Castle. They are a series of terraces, which climb up from Valdštejnská in Malá Strana to a level where you can just about bang your head on the castle wall.
I mentioned the hydra, the mythical creature, which grew additional heads every time one got chopped off. My Prague bucket list is a bit like that. For every sight on my list I get to tick off, two or three more take its place!