The hill above Piskopiano contains a nice crag which is illuminated at night. However, visiting the crag is quite a challenge - find the path up to the top and then find the scramble down to find the cache.
Note: as for any tough cache, this is attempted at your own risk. The rating assumes you do the long walk in and out from the villages below the crag (using a 4x4 doesn't get the full T5 experience). The rating reflects the long walk and the scramble (grade 1) to get the cache.
The cache is in a pretty obvious hiding hole once you get to the location, so don't waste time searching under every rock and stick. You also do not need to cross any fences, except at the stiles in the gates.
Approach shoes would be useful, but the scrambling can be done OK in trainers.
Visiting the nearby peak with the ariels at the same time for a great view is also recommended.