Quite an interesting place to be, especially because it’s in the neighbourhood of Thamel, which otherwise is very crowded place and full of shops, vendors and hustle and bustle of typical back-packer's hub.
The Garden of Dreams is serene with a pond in centre and four different monuments in four opposite sides. The sculptures are influenced by European garden and the ambience is spectacular. We visited there in late afternoon and stayed there till it was dark. The lighting placement was very creative and made it worth staying there till late.
Tip: You could carry light snacks; arrive in daylight and if possible stay until the place glows in light (interesting for night photography fanatics)