The valley holds between eight and ten tumuli, depending on which source you trust. Tibetan tradition claims that all kings from Drigum onward were buried here, but the visible mounds are generally identified with rulers from Songtsen Gampo, the founder of the Tibetan Empire, through Ralpachen, including two princes. The roster reads like a dynasty in stone: Mangsong Mangtsen, Tridu Songtsen, Gyangtsa Laban, Tride Tsuktsen, Trisong Detsen, and Mune Tsenpo all rest here, each mound a chapter in the story of Tibetan unification. Some scholars count nine mounds; others insist on eight or ten. The disagreement itself speaks to how long these tombs have sat unexcavated, their contents a matter of textual tradition rather than physical evidence.

The ancient Tibetan Annals describe what lies beneath Songtsen Gampo's mound with remarkable specificity. The inner tomb is said to contain five halls and a central burial chamber roughly 100 square meters in area and 13.4 meters high. The king's silver coffin rests at the center, surrounded by statues of Sakyamuni and Avalokitesvara. A coral statue of Lord Loyak Gyalo is positioned at the head of the coffin to provide eternal light for the dead king. At the foot lies a cache of pearls weighing 35 kilograms, wrapped in silk, symbolizing the king's share of wealth. On the left, the armor Gampo wore on his military campaigns. On the right, the golden horses and riders sacrificed alongside him. Whether these descriptions are faithful records or embellished legend remains unknown, because no formal excavation has ever been attempted.

A small temple sits above the burial mounds, rebuilt in 1983 with restored murals and maintained by just three monks. Inside, a statue of Songtsen Gampo occupies the center of the altar, flanked by his two wives: Princess Wencheng of China on one side and Bhrikuti of Nepal on the other, holding a crystal ball. The arrangement captures Gampo's diplomatic genius. He married into both neighboring powers, securing alliances that helped build the Tibetan Empire into a force stretching from Central Asia to Bengal. Eminent ministers stand to the side, including Thonmi Sambhota, the philologist credited with creating the Tibetan written script. Behind them, a crowned Maitreya faces outward with two Sakyamuni figures, while an 8th-century mural on the right wall depicts Indian deities, a reminder of the cultural currents that flowed through this valley.

The visible tumuli represent only a fraction of the valley's royal dead. Tibetan history texts including the Grand Ceremonies of the Wise and the Chronicle of Tibetan Kings and Officials record a total of 35 tombs spanning from the 29th King of Tibet to the last, divided into groups centered in separate areas throughout the valley. The scale invites comparison with Egypt's Valley of the Kings and Persia's Naqsh-e Rustam, but the Tibetan site remains far less studied. Scholars continue to debate whether Songtsen Gampo truly lies here or was interred in the Jokhang Temple in Lhasa instead. The absence of excavation keeps the question alive, preserving the tumuli in a state somewhere between archaeological site and sacred ground, where faith and evidence have yet to be reconciled.