The Most Beautiful English Word

Remember how J.R.R. Tolkien said the following:

Most English-speaking people … will admit that 'cellar door' is beautiful, especially if dissociated from its sense and from its spelling. More beautiful than, say, 'sky', and far more beautiful than 'beautiful' … Well then, in Welsh, for me cellar doors are extraordinarily frequent

Cellar door is indeed a beautiful word. However my contender for most beautiful English word is aviary.

a large cage, building, or enclosure for keeping birds in

Not only does it sound very pleasant to the ear, the concept of a building full of birds is very alluring.