KABUL, Afghanistan (AP) — Perched high above the southern edge of Kabul’s old city, the imposing fortress of Bala Hissar has endured centuries of invasions, uprisings and conflict that scarred Afghanistan and left the citadel crumbling.

Now, an extensive, yearslong project by the Aga Khan Trust for Culture, or AKTC, is painstakingly conserving Bala Hissar. The aim is to turn the site into a public archaeological park, complete with landscaped gardens, restaurants and a museum.

Despite decades of neglect and war, archaeological treasures gradually unearthed within the walls of the strategic fortress in the Afghan capital are revealing more than two millennia of the country’s tumultuous history.

‘Like a submarine coming out of the ocean’

The excavations are uncovering an astonishing wealth of finds, from evidence of ancient human habitation to the remains of a Buddhist monastery and the luxurious baths of a Mughal palace.

“We never thought we would find so much,” said archaeologist Babak Rafiei-Alavi,…