This pillar isn't just a cenotaph for Frandar Hunding. It's where his ancestors hid his treasures! Hunding was the greatest hero of Bhosek's people. Why he never tried to crack open the monument is beyond me.
I don't know much about stonework. I can't exactly ask around, can I? If Bhosek catches wind of what I'm doing, he'll take it all for himself.
But how hard can it be? Hit the stone with a pick until it crumbles, then plunder everything inside. I'm sure to find a fortune behind those walls!