noun
indoor swimming pool
Refers to a swimming pool located inside a building, as opposed to an outdoor pool (屋外プール).
このスポーツクラブには屋内プールがあります。
This sports club has an indoor swimming pool.
冬でも屋内プールで泳げます。
You can swim in the indoor pool even in winter.
屋外プール means 'outdoor swimming pool', contrasting with 屋内プール.
Compound of 屋内 (indoor) and プール (pool, from English 'pool').