Keitakuen Gardens. Osaka, Japan.

So this has been one of my favorite places of all time and definitely the nicest garden that I have ever seen. We found this place by complete accident while walking through Tennoji Park. It cost 150 Yen to enter and it does close early (like most things here) so keep that in mind if you plan on taking a trip there. Here is some background info that I found:

A formal Japanese Chisen-kaiyushiki garden (Japanese garden with a pond in the center) within the Tennoji Park. It was donated to Osaka City in the 15th year of the Taisho Period (1926) along with the main residence by Kichizaemon (pen name of Shunsui), the 15th heir of the Sumitomo Family, a wealthy merchant of Osaka since the Edo Period. Centered on a big pond with an island, the garden creates a landscape that is full of variety, with artificial hills in three directions. The walking path, steppingstones and bridges are strategically placed, and there are also a teahouse, a summerhouse, a gazebo, etc. The designer and builder of this garden is Jihei Ogawa, known as Ueji, a famous landscape architect who established the modern landscaping style, and is known for building major gardens such as those of the Kinmochi Saionji residence of Tokyo, Heian Shrine, and Maruyama Park from the mid-Meiji Era to the early Showa Period. This garden was named Keitakuen (with different kanji), reflecting Shunsui's gratitude toward "blessings of his ancestors," but was renamed with the current kanji upon completion. The main building of the Osaka Municipal Museum of Art, which can be seen when looking from the back of the garden towards the entrance, is the main residence of the Sumitomo Family, which was donated at the same time. Source: http://www.osaka-info.jp/en/facilities/cat7/post_155.html

Here is the video but it doesn't do it justice, hopefully you can go and check it out in person one day.