The Department of Homeland Security has opened the floor to bids from contractors interested in building President Donald Trump's proposed U.S.-Mexico border wall, and one Miami-based firm’s pitch is cutting-edge.

DOMO Design Studio is proposing a wall that may not look like the impenetrable, great wall Trump described during his campaign. In its bid, the firm pitched a sustainable border developed predominantly using shipping containers.

This border would mimic natural elements and include waterways, a terrain and even a mixed-use urban area with housing units, shopping and public art. Politico reports DOMO’s drawings resemble that of an innovative city park. This design would be more about unity than division, DOMO principal architect Francisco Llado said, adding this option would be both functional and beneficial to society.

The latest DHS report said the president's border wall would cost $22B and take at least three and a half years to construct. That price tag is nearly twice as much as the previous $12B to $15B estimates, and contrary to Trump’s famous campaign promise, but experts said the recent DHS report takes into account land the administration will have to secure through eminent domain laws.