After a period of ascetic in Yen Tu, the Emperor Tran Nhan Tong left the mountain and went around villages, teaching people to omit vulgar words and good practice of ten good acts, offering medicines to the poor. In May 1307, his excellency the Emperor took the veil in a small temple in Ngoa Van. In November 1308, his Excellency the Emperor attainednirvara in Ngoa Van temple which was then venerated as the Holy land of Truc Lam Zen Sect.

After Tran Nhan Tong achieved Buddha hood, Phap Loa cremate him immediately in Ngoa Van, obtained thousands of pearl-like śarīras. A portion of hispearl-like śarīras were enshrined in the the King – Monk Tower at Ngoa Van temple, another portion was taken for enshrinement in many other places includingDuc Tomb, Pho Minh tower ... the Holy Land of Ngoa Van temple was then built and expanded into a large temple complex at the order of Phap Loa. Since then, the Ngoa Van pagoda tower complex has been constantly being expanded.

Visiting Ngoa Van today, tourists can also see the King – Monk Tower, Ngoa Van temple and many other architectural relics,works which were built during Tran dynasty and other dynasties.