For more than two decades, archaeologist Calliope Limneos-Papakosta who directs the Hellenic Research Institute of the Alexandrian Civilization, has been doing excavations and been going on expeditions in an effort to find the tomb of Alexander the Great.

Papakosta had been digging for 14 years at sites around the Shallalat Gardens, a public park in the heart of Alexandria, Egypt without much progress.

Moments before Papakosta gave up, a bit of soil shifted in the last pit and her assistants called her over to inspect a piece of white marble poking out of the dirt, National Geographic reports.

“I was praying,” she says. “I hoped that it was not just a piece of marble.”

“I have a dream,” she says, “and I will go on until I fulfill it,” the woman that has gone 35 feet under modern-day Alexandria said.

The discovery, she adds, was her “greatest moment.”

Her almost life-long journey, titled ‘The Lost Tomb of Alexander the Great‘ will premiere on National Geographic in the U.S. on Monday, 4 March.

“This is the first time the original foundations of Alexandria have been found,” says Fredrik Hiebert, archaeologist in residence at the National Geographic Society.

“It gave me goosebumps to see it.”

While Papakosta keeps digging, audiences can delve into the benefits of electrical resistivity tomography (ERT); a modern method she uses to determine where to dig.

ERT passes an electrical current into the soil to measure resistance and detect subsurface objects. So far, her team has identified 14 anomalies that may be structures far beneath the ground, uncovering more and more of the Alexandria’s ancient royal quarter whilst engineering an elaborate system of pumps and hoses to keep the site dry enough to excavate

“I’m happy that I did not give up when I first arrived at the water table. I was insistent and continued. I go on.”

“For sure, it’s not easy to find it,” she says. “But for sure, I am in the centre of Alexandria in the royal quarter, and all these possibilities are in my favour.”