I think it looks more like an old-fashioned high-top shoe, with a beat-up heel extension to make up for a slightly shorter leg (probably broken and badly mended), and the yellow dot is the eyelet for the laces or a place to attach a rosette. I can imagine this as the shape of a shoe someone in the Alatriste books wore...(but wait--I was looking sideways to the LEFT...and now it looks like a shoe either way.) Maybe it was once a boot, but the top was hacked off with a dagger (hence the raggedy edge up there near the Med) when his leg was broken, and he couldn't afford new shoes or boots, so a friend whittled a sort of peg and nailed it into the heel (or maybe it was a higher-heeled boot--many were) and the sole kept coming loose, and the whole thing got more and more misshapen the longer he wore it and now he's dead and it's all moldly and green, in a puddle of water reflecting the sky.
