hills and fields; countryside
Refers to the natural landscape of mountains and fields, often evoking a rustic or rural setting.
He grew up running around the hills and fields.
The countryside of this region is beautiful.
Every weekend, he walks through the hills and fields, enjoying nature.
This flower is a wild species that grows in the hills and fields, not something you'd see in a garden.
As a child, I used to run around playing in the hills and fields.
自然 is a broad term for nature in general, whereas 山野 specifically points to the physical landscape of hills and fields.
都会 means 'city,' the built-up urban opposite of the untouched natural landscape suggested by 山野.
wildflowers and wild grasses; wild plants (as objects of beauty)
Compound of 山 (mountain) and 野 (field). The reading さんや is the on'yomi of both characters.