A petition to save Plantasia in Swansea gained more than 1,600 signatures in 2015, and the council agreed to invest £1.1m to secure its future.
The Parc Tawe attraction has been given a new layout and is designed to recreate the smells and sounds of a real rainforest.
It is home to animals such as piranhas, crocodiles, parrots and monkeys.
It is hoped the renovated attraction, which first opened in 1990 and attracts about 80,000 visitors a year, will draw more tourism, with its layout designed by the team behind attractions at Alton Towers and the London Dungeon.
Robert Francis-Davies, Swansea Council’s cabinet member for regeneration and tourism, said.”People are becoming far more interested in the environment and the importance of plants.
“We want to make sure children from an early age understand the importance of the environment.”
Heather Morgan, from Parkwood, which is taking over the daily running of the rainforest, said: “I can’t think of many other cities that can boast about having a rainforest in their centre.”