Don Cornelius Likes My Sole Drain

The picture above shows the north retaining wall going up the edge of my property, from Spring Street up to the bay window in the dining room. The granite slabs atop this wall stop at the back corner pillar of the wrap-around porch, and in that picture at the top, the sunlight catches just a bit of an out-jut at that point in the wall. This is what you're seeing:

For all these year's I've been in the house, I imagined this strange feature of the wall was a planter or something odd like that, which may not be a particularly reasonable explanation. But what I saw was a squared out place that appeared to be full of dirt, and I figured it was time to plant some great summer flowers in it.

But it's not a planter. Once I removed a couple of inches of soil and sand with a small scattering of weeds, I found myself staring into a drain:

It must've caught run-off from the porch gutters and downspouts, and I think it must tie directly into the street sewer. A sort-of-interesting find, and that's about it.