A gay bathhouse, also known as a gay sauna or a gay steambath (uncommonly known as a gay spa), is a public bath targeted towards gay and bisexual men. In gay slang, a bathhouse may be called just "the baths", "the sauna", or "the tubs". Historically, they have been used for sexual activity.
Bathhouses offering similar services for women are rare, but some men's bathhouses occasionally have a "lesbian" or "women only" night. Some, such as Hawks PDX, offer so-called "bisexual" nights, where anyone is welcome regardless of gender.
Bathhouses vary considerably in size and amenities—from small establishments with 10 or 20 rooms and a handful of lockers to multi-story saunas with a variety of room styles or sizes and several steam baths, hot tubs, and sometimes swimming pools. Most have a steam room (or wet sauna), dry sauna, showers, lockers, and small private rooms.
In many countries, bathhouses are "membership only" (for legal reasons); though membership is generally open to any adult who seeks it, usually after paying a small fee. Unlike brothels, customers pay only for the use of the facilities. Sexual activity, if it occurs, is not provided by staff of the establishment, but is between customers with no money exchanged. Many gay bathhouses, for legal reasons, explicitly prohibit and/or discourage prostitution and ban known prostitutes.
Records of men meeting for sex with other men in bathhouses date back to the 15th century. A tradition of public baths dates back to the 6th century BCE, and there are many ancient records of homosexual activity in Greece. In the West, gay men have been using bathhouses for sex since at least the late 19th and early 20th centuries, a time when homosexual acts were illegal in most Western countries and men who were caught engaging in homosexual acts were often arrested and publicly humiliated. Men began frequenting cruising areas such as bathhouses, public parks, alleys, train and bus stations, adult theaters, public lavatories (cottages or tearooms), and gym changing rooms where they could meet other men for sex.