Syon Park Gardens in Brentford - West London. You have to pay to get in but it's a quiet oasis of green + you can take in your own food & drink :-) http://www.syonpark.co.uk
Cap d'Antibes - a beautiful place on the Mediterranean in the South of France.
Pigeon Point - Tobago is an absolutely stunning place. It's amazing to see palm trees so close to the waters edge. The sand is so white, full of little shells and the sea is so blue and shallow :-)
Balaruc les Bains, a small fishing village in the South of France