Bezos shared a video on Tuesday of the giant clock’s construction inside a mountain in West Texas. It would be 500-feet tall once completed, and will stand as “a symbol for long-term thinking,” the Amazon founder said in a tweet.

Bezos is one of several financial backers of the 10,000 year clock, which is being built by the non-profit cultural institute, the Long Now Foundation. One of the foundation’s objectives is to foster the notion of long-term critical thinking in today’s age of rapid-fire online communications and fast-paced living.

Unlike conventional clocks, the 10,000 year clock is not designed to keep track of seconds, minutes, or hours. Instead, it’s been designed to tick once a year for approximately 10,000 years.

Installation has begun—500 ft tall, all mechanical, powered by day/night thermal cycles, synchronized at solar noon, a symbol for long-term thinking—the #10000YearClock is coming together thx to the genius of Danny Hillis, Zander Rose & the whole Clock team! Enjoy the video. pic.twitter.com/FYIyaUIbdJ

— Jeff Bezos (@JeffBezos) February 20, 2018

The Long Now Foundation said that the clock will occasionally play music using it bells, and that each time it will be a melody that it has not played before.

“The Clock’s chimes have been programmed to not repeat themselves for 10,000 years,” the foundation said. “Most times the Clock rings when a visitor has wound it, but the Clock hoards energy from a different source and occasionally it will ring itself when no one is around to hear it.”

The Long Now Foundation has not said when the clock would be completed, but said on its website that it would be open to the public once finished.

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As Fortune’s Anne Vandermey previously wrote, the clock is “more of a conceptual art piece designed to encourage people to be good stewards of humanity’s distant future.”