There are plenty of disputes in the world of D.C. education policy. But there also are a few universally held truths, including that the city’s aging Dunbar High School — a dingy, dark and nearly windowless high-rise — was not built to inspire learning.

“That building was built like a prison,” Principal Stephen Jackson said.

Now the 1970s-era behemoth stands empty, awaiting demolition as Jackson and an array of D.C. officials and alumni — including Mayor Vincent C. Gray, Class of 1959 — prepare to cut the ribbon Monday on a new Dunbar next door.

The $122 million building, constructed around a central armory with soaring windows, is light-filled and airy. It appears full of promise for a school once known as the nation’s preeminent black public high school but one that has struggled in recent decades.

Founded in 1870 as the Preparatory High School for Colored Youth, Dunbar was the country’s first public high school for African Americans. It produced generations of black leaders in fields such as law, education, science, engineering and civil rights.

But as schools were integrated and middle-class families moved to the suburbs, Dunbar didn’t escape the problems that beset so many inner-city schools. By 2012, about six in 10 students graduated on time and fewer than one-third were proficient in reading and math.

The new building — at First and N Streets Northwest, the site that housed Dunbar from 1917 until 1977 — is meant to inspire students in part by connecting them with the past. The theater features a restored Steinway piano, first used a century ago at Dunbar. The armory is home to a striking image of the school’s namesake, poet Paul Laurence Dunbar.

And the names of influential alumni are inscribed in hundreds of silver floor panels embedded throughout the school: Charles Drew, the pioneering physician; Edward Brooke III, the first African American elected to the U.S. Senate; and Eleanor Holmes Norton, the District’s delegate to Congress.

Some of the panels have been left blank, a message to students that they, too, can do great things.

“We let students know that this empty plaque could be you someday,” Jackson said.

The new Dunbar, like many of the D.C. school buildings that have been rebuilt in recent years, boasts all manner of energy-efficient features, from geothermal heating to solar panels.

There is a gleaming gymnasium, an eight-lane swimming pool and a weight room. Classrooms are stocked with flat-screen televisions, interactive whiteboards and digital projectors.

But the most important feature of the new building might be the simplest: walls.

The old Dunbar was built in the mid-1970s without walls to separate classrooms. The “open” concept, popular at the time, turned out to generate chaos, din and distraction for generations of teachers and students.

In the coming months, there is sure to be discussion about whether and how Dunbar will be able to fill its new space. The school is built to house 1,100 students — far more than the 500 who attended last year.

But for now, the Dunbar community is celebrating. School officials and alumni have planned a week-long dedication with daily tours and events, starting with the ribbon-cutting at 3:30 p.m. Monday and including a speech by comedian Bill Cosby on Wednesday afternoon.

“A hundred years from now, they’re going to be talking about what we’re doing here,” Jackson said. “It’s great to be a part of history.”