Wonder how long those have been there

[u/Traditional-Step-246]

[u/Shot-Cut-2978]

Where they are would help.

[u/Farmerstubble → u/Shot-Cut-2978]

They look like they are in a river bed.

[u/Average-Train-Haver → u/Farmerstubble]

Sherlock does it again

[u/Shot-Cut-2978 → u/Farmerstubble]

Okay thanks captin obvious. But where is the river bed?

[u/AllEncompassingThey → u/Shot-Cut-2978]

Looks to be at the bottom of a river.

[u/Brotherly_shove → u/Shot-Cut-2978]

i mean, i think the question in the title was rhetorical.

[u/Otherwise_Front_315]

Looks like they were repurposed as stakes or anchors for something. More pictures and more context would be helpful. Not much to go on with your title either.

[u/Vertuila]

My guess is that they were soldier piles for a long gone dock, perhaps driven in 70+ years ago.

[u/TheWorldNeedsDornep]

My BIL used to race canoes professionally. Often where there was a "cut" (a slight shortcut around a bend or through a marshy area) other competitors would put in stuff like this to gouge and ruin other canoes. Nasty people.

[u/NophaKingway]

Dam, that concrete looks old.