According to the White House budget plan released on March 16, Trump is seeking to spend $2.6 billion to plan, design, and start constructing a wall along the US-Mexico border. An additional $3.3 billion would go toward building new detention facilities for undocumented immigrants, hiring 1,500 immigration and border control agents, and expanding a digital system, called E-Verify, that allows employers to see if people are eligible to work in the US.

This is just a preliminary proposal. The US Department of Homeland Security says the total cost of the border wall project could be around $21.6 billion.

The wall — and everything that would come with it — is easily one of the largest infrastructure investments in the president's plan.

Three New York City-based designers have envisioned a more cost-effective (and amiable) alternative: a bi-national park that runs the entire length of the US-Mexico border.

The designers, Wesley Thompson, Hiroshi Kaneko, and Josie Baldner, won second place in the international design competition "Building the Border Wall." The jury, made up of architects and artists, asked for "bold humanitarian solutions, creativity, and innovation to bear on alternative ideas of a border wall."

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The Border Park designers propose a nature reserve where people from both sides could hike and camp. The national park services from the US and Mexico would maintain the area equally, Thompson tells Business Insider. Both countries would generate money from visitors like any other national park.

"It would only make sense to have both the US and Mexico invest in something together," the designers say. "It’s a shared resource with shared benefits and ownership. Ultimately, we believe mutual cooperation can destigmatize the border, promoting communication, and a greater respect for each country."

Spanning around 1,900 miles, the Border Park would feature native flora and fauna, including cacti, dunes, rivers, a beach, and agricultural fields. In addition, the team considered animals, like ocelot, lizards, desert bighorn sheep, and bison, for the park. (A wall, on the other hand, would likely disrupt migratory and habitual patterns.)

Right now, the design is just a concept. Building a park rather than Trump's proposed 55-foot-tall fence is most likely an impossibility. But with the design, the creators hope to "break down the binary that the wall represents."

"We have friends who have crossed the border. We don’t want something so aggressive or imposing to continue to be the first experience people have coming into this country," they say. "It’s a broken system."

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For the designers, a shared park is the antithesis of a wall.

"We engage with parks in a very different way: they are places we protect, have a desire to maintain, places we visit and enjoy. This creates a zone to interact with and explore. A park is, in a way, a dynamic and diverse boundary that can still demarcate and serve as a national border," the designers say.