The doors of Rotorua's Bath House opened on August 13, 1908, with a golden key and a flurry of fanfare.
The land where it sits, at the heart of the Government Gardens, was donated by Ngāti Whakaue in 1880 as part of the Fenton Agreement.
After the eruption of Mt Tarawera, there was a downturn in tourism to the area.
By 1901, when the Department of Tourist and Health Resorts was founded, the Government Gardens was taking shape.
The gardener's cottage had been built to house the head gardener, the band rotunda and tea rooms had been constructed and the Prince's Gate arches had been put in place at the Queen's Drive entrance.
Englishman Dr Arthur Stanley Wohlmann arrived in Rotorua in 1902 as the government balneologist to study the therapeutic use of baths.
Rotorua Museum volunteer and creative communities lead Julie Parsons said he had travelled the country seeking the perfect spot to build a bathhouse.
The site for the bathhouse was chosen but, scared to dig down in the geothermal location, the hill was instead built up against the building.
"The build began in 1905 and by 1908 they had run out of money," Parsons said.
"The women's wing wasn't completed, which was really of no great consequence to them because most of the people using the spa were men."
The building was constructed in a Tudor method with concrete panels, made of moulded pumice, and timber.
In 1908 Rear Admiral Charles S. Sperry and Prime Minister at the time Joseph Ward opened Rotorua's Bath House with a golden key made especially for the occasion.
"Right from the start it was a medical facility, run by doctors and nurses and people visited the spa for their health," Parsons said.
By 1951, two world wars, growing maintenance costs and changing medicine saw the Bath House struggling.
"Everything was against it," Parsons said.
In 1966 it closed for treatments and moved operations to QE Health.
Malcolm Short, Ngāti Whakaue, said the land had been donated for the benefit of people and that was what the Government Gardens and Bath House had achieved.
"It is an enormous tourist attraction and one of the most photographed buildings in New Zealand.
"Together they are a lovely feature for Rotorua, so Ngāti Whakaue is pleased to see it is being restored to its former glory, we're very happy with it."