The three-story entrance building, designed in the Moorish style, had twin towers soaring 112 feet into the air on the two front corners. Patrons passed a smoking room on the left and a ladies parlor on the right as they entered. There was a fine café on the top floor, billiard and card rooms, a saloon, tea rooms, a gym, and a balcony dance floor. But the water was the real attraction.
The pool was 125 by 60 feet rippling beneath a 40-foot arched roof. At the south end water cascaded over rocks creating an artificial grotto. There were diving boards for every level of daredevil from five feet to 60 feet. A waterslide extended into the pool from the first balcony and for the particularly courageous a trapeze hung down from the roof.
You would expect people to be dressed in their finery for dances and special events at the Nat, but they didn’t undress much to enter the pool in the early years. Men wore two-piece swimming suits consisting of a short-sleeve shirt and long shorts, while women dipped their toes wearing below-the-knees bloomers and knee-length skirts. Their blouses, which were considered a bit daring, featured puffed sleeves. Just to assure flashes of skin were kept to a minimum, the ladies also wore long stockings.
Travelers to Boise seldom missed a chance to see the Natatorium in the early days. It was the biggest swimming pool in the West. If visitors craved even more entertainment, they could chance the carnival rides at the adjacent White City Park, one of many across the country playing up on the nickname of Chicago’s 1893 Columbian Exhibition. The park had a fun house, a roller coaster, a lagoon for paddle boats, a miniature train, and a hot air balloon launch pad.
The Nat was the site of countless weddings, fund-raisers and even inaugural balls during its reign on Warm Springs Avenue. The temperature of the springs that fed the Nat was 170 degrees coming out of the ground and had to be cooled to a pleasant 85 for the pool.
Hot water was what made the Nat possible, but it was also hot water that proved its demise. Much of the classic building was built from wood. Steam and humidity took their toll on the structure.
An ad for the Natatorium that ran on April 29, 1934, led with the line, “Swimming at the NATATORIM is one sport that is not affected by weather.” The irony of that came to light a few weeks later in July, when a freak windstorm brought one of the humidity-weakened roof beams crashing down into the pool, miraculously missing the swimmers.
The owners soon tore down the deteriorating building. There was talk of reconstructing it, but talk was all it was. The City of Boise eventually bought the property and opened a new outdoor pool on the site. There’s a functional support building there behind Adams Elementary. It’s unlikely it will ever generate quite the love that Boise had for the Nat during its 42-year history.