What is this?

[HungLikeJesus]

Originally Posted by Uisge Beatha

You could be right (I originally dismissed the appearance in picture #1 as such), but the second and third photos do show trapezoidal pieces. They also seem to indicate a spread in the border of the marks on the patio.

Not optical illusion; optional illusion. It's not for everyone.

And is it an Ark or an arc?

With the exception of the split board, I think that they are all straight 2x8 or 2x10s.

[TheMercenary]

Originally Posted by HLJ

Not optical illusion; optional illusion. It's not for everyone.

And is it an Ark or an arc?

With the exception of the split board, I think that they are all straight 2x8 or 2x10s.

Fish eye lense camera. Straight boards. Looks like fencing. They all split like that when you pull them off to replace them. Who knows.