What looks from the outside like an insurmountable bouncing castle, upon entry becomes a vehemently colourful yet surprisingly placid environment - not unlike what we can only imagine one would find in a womb.

Exxopolis by Architects of Air is an immersive ‘luminarium’ currently residing on the Opera House forecourt. What is a ‘luminarium’? Essentially, it’s a trippy pneumatic structure of tunnels and domes – not quite labyrinth, not quite inflatable cathedral – that contacts light like an aquarium contains water. Visitors enter an airlock chamber and are engulfed by salient multicolour and a meditation-aiding soundscape. The colour and mood within the structure varies according to the weather, while the deceptive opaque hue on the external face remains unchanged.

Architects of Air is a Nottingham-based project of photographer Alan Parkinson, who became interested in shapes in nature, like plant life and bubbles. Taking inspiration widely – from bazaars in Iran to repeat patterns and geometrical shapes found in Islamic architecture – the project initially started at a community level with help from young offenders.

According to Exhibition Manager Shanti Freed, the concept of inflatable environments has been floating around since the ‘60s, but Parkinson constructed the first luminarium of this kind in the early ‘90s. Gaining momentum and complexity over time, Architects of Air has been caravanning around the world delighting audiences from America to Lithuania, participating in summer programs, art exhibitions and the like.

Exxopolis is inspired by designs found in cathedrals and mosques and its ‘stained-glass’ windows borrow from Penrose’s non-periodic tiling patterns. Interestingly, the construction is hand-made, taking a small group of people around four months to sew and zip together.

This is actually the second luminarium to find itself in Sydney. In 2011, Architects of Air brought us a luminarium grandly titled Mirazozo, which was visited by about 44,000 people.

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If you feel comfortable in small spaces, you can get immersed in Exxopolis’ colourful PVC until 27 January from 10am – 7.30pm for $15.