There is a small parking just above the beach. To find the cache you need to go down the stairs. The coordinates are not very precise, when you stand back to the sea, the cache is on the right side of the valley. The spoiler photo and the the hint will surely help you. It requires minimal climbing to get it.
The cache is medium size, it contains a logbook and some small items.
It is believed that if you find on the beach a pebble with a hole and take it with you, it will bring you luck for the whole year.
From Wied il-Ghasri you can have a nice walk at the seashore to the Gozo saltpans on the way to Marsaforn, to the Second Azzure Window, or to the lighthouse, where some other caches are hidden.
Enjoy :-)