Dip in kitchen worktop

[OldRat]

Hi
Just getting round to doing some tiling, (after 10 years of living here, still, mustn't rush these things)
Came across the problem that the worktop seems to be dipping in places but over the length of the run it is level.

I hope this is better explained in the pictures, but any ideas how it was caused and possibly how to correct please?

Thanks very much

[dewaltdisney]

Under the kickboard, you will see the base cabinet support legs are adjustable. If you turn the feet it will lift cabinet to take out that dip.

DWD