any idea what this could be for?

[rockduro]

hello everyone. I was at a farm south of Cali Colombia along the Cauca river. I often go down and look for cool rocks if the water is low enough. Yesterday I found this and I am curious if anyone has any idea what it is or could be for. Thanks!

[antmike915]

looks natural to me but I'm not familiar with material from your area. Someone will be along to clarify.

[Kentucky point]

Sorry, but it is an un-altered, natural rock.

[Jethro355]

I would say natural except for the grooves in it. It looks like it has been lashed to something, though I couldn’t guess what?

[rockduro]

thanks for the all the responses, I thought the grooves were not natural as they are perfectly straight and on flat planes. Im consulting some people that might know here in colombia.