I washed my hands at the hand-washing area in the park.
This campsite has two washrooms.
Euphemistic or indirect way to refer to a toilet, similar to 'washroom' in English. Cross-referenced with 便所.
See also: 便所
Excuse me, where is the restroom?
洗面所 specifically refers to a washroom or lavatory for washing face and hands, often inside a home, whereas 手洗い場 can be a simpler outdoor or public facility.
Standard full spelling for a hand-washing area or washroom.
Abbreviated spelling without the okurigana い; less common but still seen.
Compound of 手洗い (hand-washing) + 場 (place). The euphemistic toilet sense developed from the idea of a place for washing hands.