As the creators of “South Park” pour millions of dollars into Casa Bonita — the iconic and nostalgic restaurant known for its cliff divers, lagoon and sopapillas — 9NEWS has reviewed hundreds of pages of plans, permits and images that show how much costly work is being done inside and outside.

The documents were obtained through an open records request to the City of Lakewood.

Westword was the first media outlet to break the news that “South Park” creators Matt Stone and Trey Parker were buying the restaurant for $3.1 million, but these documents reveal the new owners are spending at least four times as much on renovations and upgrades.

“The total cost of alterations for the primary space as applicable to this provision are approximately $12,125,000,” a response from the project contractor to the City of Lakewood says in the documents.

For the most part, the plans indicate the iconic elements inside Casa Bonita such as the dive pool, Black Bart’s Cave and seating areas will undergo repairs and improvements to match the original feel of the restaurant.

Yet the kitchen and bathrooms are undergoing substantial renovations while audio and visual elements are being improved, such as new projectors, loud speakers, lighting and security cameras throughout the restaurant.

A significant and costly focus of the renovation is creating ramps for accessibility to make the restaurant more ADA compliant, a new vertical platform lift and making more room for “increased accessible seating.”

The plans also indicate the contractor applied for a permit to remove approximately 700 square feet of tile that contained asbestos.

A permit says a “complete renovation of indoor pools and water features and outdoor water feature,” will cost $210,000.

Blueprints and plans reveal the dive pool will undergo a renovation with new bonding. The pool, which is 13-and-a-half-feet deep and holds 48,000 gallons of water, will get new steps for the divers that match the artificial rock on its rim.

The plans also reveal a new fountain out front with LED lighting.

The plans also indicate improving the audio and visual elements will cost $1.3 million dollars, which includes a new sound system throughout the restaurant and security camera system.

While it’s unknown what it looks like on the inside today, photos obtained by 9NEWS through the documents reveal that the restaurant was gutted in numerous areas as work began in 2021.

A report by an asbestos inspection company contained dozens of images showing the restaurant like people have never seen it before — from the poolside areas to the iconic game room empty of tables and games.

The photos also show cracked floors in need of repair and gutted kitchen areas.

In a recent interview with The Denver Post, Stone and Parker compared the project to the show “Kitchen Nightmares” and didn’t give an opening date.

While the restaurant was expected to open this summer, the owners hinted to The Denver Post that much more work needs to be done and an opening date can’t be set yet.