Idyllic
Etymology
From "idyll," through Latin "idyllium" from Greek "eidyllion," a diminutive of "eidos" ("form, shape, picture"). An "eidyllion" was a short descriptive poem, often of pastoral scenes; from those idealized little pictures came the sense of something flawlessly peaceful and picturesque.
adjective · /eye-DIL-ik/
Extremely peaceful, picturesque, and perfect, like a scene in a pastoral poem.
What it names
The word for a setting or moment so serene and lovely that it feels like an untroubled ideal.
Example
They spent an idyllic afternoon by the lake, with nothing to do and nowhere to be.
Related idea
Bucolic points specifically at rural charm; idyllic points at flawless, blissful peace, whether rural or not.