The ceiling has since been removed and women regularly sun themselves in front of the pavilion on a pontoon in the lake - some of them even topless, in the middle of the city.
Moral standards may have loosened, but men are still not allowed to enter - at least not during the day.
Men are excluded until the evenings when the Frauenbadi turns into the Barfussbar (Barefoot Bar), a creation of Jonas Thiel, who set up table and chairs around the pool. Guests of both sexes are welcome, but shoes are banned from the front door in.
"Out of respect to the women, we do not walk around their lounging surfaces with shoes on," said Thiel.
The Barfussbar has grown into a cult bar as guests look directly out onto the towers of the Great Minster, a city church surrounded by the lights of the Old Town.
As part of the baths' anniversary, there are art exhibitions as well as a very special exception. On certain days, men are being allowed to swim in the Frauenbadi - either in the pool with river water or right out in the open Limmat.
Those who are thirsty can even take a sip of the river water. The waters of the Limmat River and Lake Zurich are of potable quality.
In addition to the style of the pools, it's the clean water which attracts so many Zurich people.
Many jump into the water before work or take a quick swim in the lake during their lunch break, not only in the Badis but wherever they have access to the waterside. Those who can afford it will take their own boat onto the water, while children and youngsters enjoy jumping from bridges into the Limmat and just drifting in the water through the city.
The fun and games of swimming in the Limmat turn into a public festival in August as hundreds gather at the Frauenbadi to climb down into the Limmat and just drift with the current to the Oberer Letten bath.
"There's nothing to win. Whoever gets there first, it's their own fault," said city guide Elisabeth Brem, who adds that Zurich natives want to enjoy their lakes and rivers, not be in a rush to get the pleasure over with.
Now what does a town with a segregated women-only pool complex provide for men? A men-only pool of course. The Maennerbadi (Men's bath), which opened in 1864 at Schanzengraben, is Zurich's oldest public baths and still remains a male preserve during the daytime.
In the evenings it transforms into the Rimini Bar with open-air films and concerts and women are allowed in as guests.
Many of the traditional baths also offer massages and wellness getaways. The main attraction for the Enge am Mythenquai lake bath is a sauna within the lake.
However the public baths are not as elegant as the ones in luxury hotels. One of the best spas in the city is high over the lake.
Visitors can go to the legendary Dolder Grand, sited on a hill, and swim and relax in a 4,000-square-metre indoor-outdoor spa with a fantastic view of the city, the lake and the Alps.
- DPA
