In California- The Sherman Gardens and Library- The 2-1/2 acres of tranquility behind the gate is one whitewashed wall and a world away from the bustle of Pacific Coast Highway. Where we always take visitors or anyone thinking about taking up gardening.
In the US (not California) The Cheyenne Botanical Garden. A different world about promise and prairie.
In the World- The RHS gardens at Wisley. Went on a whim on the recommendation of hospitality at the hotel we were staying in at Farnborough. I could have spent the week in just the bookshop. Then there are the unending gardens. With espaliered fruit trees and plant grown in greenhouses I could brag about because they grow in our yards here):- I would give up a year of my life to spend a month there.