Despite the rain the Affinity sculpture has lit up Rotorua's City Focus.
Organisers were thrilled as Affinity was switched on during the opening ceremony on Monday night.
Rotorua Lakes Council project manager for Affinity, Mandy Godo, said the opening night went well, despite the challenging weather conditions.
"The rain stopped just at the end of speeches, as people had their first chance to interact with the sculpture, it was perfect," she said.
"Children really enjoyed it, the lights and the stories."
Ms Godo said people came and went throughout the evening but she estimated between 150-250 people showed up.
"It's free and available for all to explore and enjoy, regardless of the weather," she said.
"It will be running every night through till April 24."
Monty Morrison opened the evening with a mihi, before councillor Karen Hunt spoke on behalf of the council.
Ms Hunt said the sculpture represented Rotorua's aim to become a dementia-friendly city.
Spanning 13m x 13m, the interactive installation was built to raise awareness for Alzheimer's disease.
The sculpture depicts the complexity and connectivity of the human brain, representing the rapid-fire transmission of messages between neurons.
Premium sponsor, health and care company Bupa was represented by director of care services and rehabilitation, Jenni Coles.
"A dementia-friendly community starts with understanding what dementia is, and Affinity is helping to do just that," she said.
"It's then about using that knowledge and turning it into action so that people living with dementia are supported to continue doing the things they enjoy."
Children's author, Alzheimer's New Zealand champion and dementia advocate Kate De Goldi rounded out the speeches.
Ms De Goldi had flown from Wellington to share her own experience of losing both her parents to dementia.