Pangri Zampa stands on the west bank of the Thimphu river just beyond the municipality's northern fringes. Although its history spans nearly 500 years, it is most famous for its role as Bhutan's Royal College of Astrology, a distinction it has held since 2003.

The monastery forms a large quadrangle with student dormitories, classrooms, and administrative buildings on the west, north, and south sides, and two temple buildings on the northeast and southeast corners. A covered bridge links the east side with the opposite bank of the Thimphu river.

The complex was built in two stages over about 100 years. Its first phase was marked by the patronage of Ngawang Chögyal (1465-1540), the 15th throne holder of Tibet's Ralung monastery and a leading luminary of the Drukpa Kagyu order. While in Thimphu, he established the old temple of Druk Phodrang at the present site, meaning "Citadel of the Dragon." Today, the temple marks the northeast corner of the quadrangle and comprises three levels topped by a gilded finial. A statue of the Buddha stands on the uppermost floor, and various dharma-protector shrines are found on the lower levels. These include altars to Yeshi Gonpo and Palden Lhamo, both of whom are fierce protector deities.

The second stage coincided with the arrival in Bhutan of Ngawang Namgyal (1594-1651), the national unifier, later dubbed the first Zhabdrung Rinpoche. A biography written by one of his students, Jamyang Pelden Gyatsho (1610-1684), records the dream that brought the Zhabdrung to Pangri Zampa. While in his native Tibet, the Zhabdrung dreamed of a large black raven that flew toward the "southern valleys" (i.e., Bhutan). In his dream, the Zhabdrung thrust himself aloft and followed the raven as it flew low over the mountains, pacing it until it landed on a cypress tree at a site he later identified as Pangri Zampa. Though the raven appeared in natural form, the dreaming Zhabdrung recognized it as Mahakala, a fierce protector of the Buddhist dharma. Mahakala is often represented with the face of a raven and is frequently called upon to vanquish evil forces. According to Tetsu Nagasawa, the episode is even written into the Tsayig Chenmo, the Zhabdrung's legal code, which identifies Mahakala as the 'donor' who provided him with sovereignty over Bhutan.

The Zhabdrung raised the temple on the southeast corner of the monastery adjacent to the covered Kabesa bridge. The upper level is the personal residence of the Zhabdrung but now houses his statue.

The architectural historian Pierre Pichard notes a close relationship between Pangri Zampa and the nearby Dechenphug Lhakhang, which stands about two kilometers west on the forested hillside. Within the Zhabdrung's temple at Pangri Zampa is a statue of a "mermaid" representing Menmo, a water goddess and consort of Genyen Jagpa Melen, the guardian deity of Thimphu, who resides at Dechenphug.

The monastery is often called upon to determine the most auspicious timing of key national events in the modern era. For example, the head astrologer ascertained the most favorable timing for the coronation of HM King Jigme Khesar Namgyel Wangchuck in 2008. Pangri Zampa also assisted with divining dates for the royal wedding and naming ceremonies for the crown prince, among other activities.

Reference: https://www.orientalarchitecture.com/sid/1571/bhutan/thimphu/pangri-zampa-monastery