Sandgate

Here is an interesting remnant from Sandgate's past.

At each end of a large retaining wall along the southern side of Alexandra Street, Sandgate, at the intersection with Southerden Street, stands a low stone post.  The stone post at the higher, western end of the retaining wall, although matching the post at the lower, Southerden Street end in size and design, is un-adorned.  The post at the Southerden Street end, as pictured, is adorned with a lion's head, which gazes out, across Southerden Street, at the wide expanse of Dowse Lagoon.

This seems to be a rather grand touch to an otherwise plain and unassuming, though large, retaining wall.

Is anyone aware of its story or how long it's been here and are there any others, similar to this, around the area or throughout Brisbane at large?