Four years after the devastating Tōhoku earthquake and tsunami, Japan is diligently working to find ways to protect coastal communities from the next one— most visibly by constructing sometimes massive sea walls, intended to halt towering waves before they reach the shore.

Already, there have been objections: the walls will destroy the view of the sea and disrupt wildlife. But construction is moving ahead, and now the plan is to build a 250-mile long wall that, at times, will reach higher than 40 feet, according to The Independent. Reporter Jon Stone writes that the proposed $6.8 billion barrier "would be made out of cement – and actually be composed of a chain of smaller sea walls to make construction easier."

But the peak of the 2011 tsunami reached 138 feet high, points out Popular Science. When the wave reached Otsuchi, a town of 15,000 people, it was 50 feet high. It easily breached the town’s 30-foot wall. Up the coast, the town of Fudai was barely touched. CBS News reports:

Decades ago, towns along the northeast coast of Japan began erecting seawalls to withstand waves of about 30 feet--the height of a terrible tsunami that struck in 1933. Kotoko Wamura was the mayor of Fudai when the town began planning its seawall in the 1960s. Wamura had been a young man when the 1933 tsunami wiped out Fudai, and the memories made him determined not to let it happen again. Wamura also remembered family stories about the tsunami of 1896, which had been even bigger: 50 feet. When it came time to draw up plans for the Fudai seawall and a later floodgate, Wamura insisted they both be 50 feet high. Many of the villagers were furious, unconvinced they needed a wall that was so expensive and so ugly, blocking their ocean view. But Wamura wouldn't back down. Fudai got the tallest seawall on the whole northeast coast.

So ultimatly, the new sea wall may be ugly, may disrupt wildlife and may not make enough of a difference. Furthermore, Kelsey D. Atherton for Popular Science points out that a sea wall might prompt people to rebuild where they shouldn’t. Still, it’s hard to dismiss any hint of protection from future tsunamis, given the disaster that struck in 2011.