Sunspot

Sunspot? from Point Rich
When I was at Point Rich, it was very hazy. The sun slowly set as a dim red ball. But there was this dark spot on the sun's disc which as far as I could tell stayed in the same location as the sun set. It almost looks like a bug on my lens, but it was visible with the naked eye as well. Is this a sunspot? Are those visible with the naked eye?
©Bill Yeaton