1. What does it mean?
산스장 blends 산, mountain, with 헬스장, gym. It usually refers to outdoor exercise equipment or a workout spot found along a hill or mountain trail.
Also written or said as sanseujang
2. The nuance
It is a casual nickname, not a promise of staffed gym facilities. Similar equipment in a park may be called 공스장, and the actual setting determines what is available.
3. Examples
“산책하다 산스장을 발견해서 잠깐 구경했어.”
I found an outdoor mountain gym while walking and stopped to look.
“산스장 기구는 비가 온 뒤라 사용하지 않았어.”
I didn't use the mountain-gym equipment because it had just rained.
Sources
References support the meaning and usage. Example sentences are written for NoCapWiki.