Alder Hills is an interesting place, it not so much hills as a large pond. The best way I can describe it is to say that it is like a dormant volcano with a crater filled with water. It is not a volcano, of course, it is the result of clay extraction some years ago and now nature has recollonised the whole area and made a very good job of it too!
Being originally heath on very sandy soil the natural vegetation of heathers (ling and bell heather) and gorse (western gorse and dwarf gorse) have spread across the inner slopes of the crater to create ideal habitat for some rare insects, including the heath grasshopper, and rare reptiles such as sand lizard and smooth snake. Not surprisingly this relatively small area, despite being surrounded by housing and industrial units, is an SSSI of some note.
The pond itself has various water lillies which appear to have been introduced and also has some exotic fish and terrapins which have been added by local people over time. Whilst lovely to look at, inmy view the pond lacks the interest of the surrounding heath.
The slopes down to the pond on the north side and the path, especially around the south side, are quite hard going so if you are not that stable and able then perhaps Alder Hills might be too much of a challenge.