Bathhouses are against the law.

CALIFORNIA CODES
PENAL CODE
SECTION 11225

(a) Every building or place used for the purpose of illegal gambling as defined by state law or local ordinance, lewdness, assignation, or prostitution, and every building or place in or upon which acts of illegal gambling as defined by state law or local ordinance, lewdness, assignation, or prostitution, are held or occur, is a nuisance which shall be enjoined, abated, and prevented, and for which damages may be recovered, whether it is a public or private nuisance.

Nothing in this subdivision shall be construed to apply the definition of a nuisance to a private residence where illegal gambling is conducted on an intermittent basis and without the purpose of producing profit for the owner or occupier of the premises.

(b) Every building or place used as a bathhouse which as a primary activity encourages or permits conduct that according to the guidelines of the federal Centers for Disease Control can transmit AIDS, including, but not limited to, anal intercourse, oral copulation, or vaginal intercourse, is a nuisance which shall be enjoined, abated, and prevented, and for which damages may be recovered, whether it is a public or private nuisance.

For purposes of this subdivision, a “bathhouse” is to be defined as a business which, as its primary purpose, provides facilities for a spa, whirlpool, communal bath, sauna, steam bath, mineral bath, mud bath, or facilities for swimming.

This law was enacted shortly after the AIDS epidemic came into the News in the 1980’s. Bathhouses were one of the primary places people could go for anonymous sex. This law was designed to curtail exposure to HIV and other STD’s.