High-quality specimens of blue/grey and more rarely, coloured, agate are found along the coast at Stonehaven. Personally, I have not spent much time collecting here, so the pieces I have below are not representative. This situation will be rectified at some as yet undisclosed future date. I imagine you yourself might have more luck?
So, why not have a gander? At the very least, if no gems are procured, you might sample a tablet ice, take a stroll to the picturesque harbour, eat a fine fish and chip supper, or dine on more refined fare in the excellent restaurant nearby.
Personally, I am always reminded to remove my hat here, and toss it into the sea.