A.Stein in the Memoirs of the Archaeological Survey of India first mentioned the site of Gumbatuna in 1930. Berger and Wright who carried out some small-scale excavation (Berger et al. 1941). Professor G. Tucci followed it in 1955-56.
The site of Gumbatuna (Gumbatuna is the plural form of “Gumbat”, the Pashto word for “dome”) is a Buddhist establishment situated on the right bank of the river Swat, 6km west of Barikot village along the metalled road leading towards Nimogram in a wide valley. The valley is broadly drained by the Swat river which flows in several braided channels through the area. The archaeological remains are scattered over a range of 1500 meters north to south and 1000 meters east to west in wides terraced fields sloping unto the hills behind, known as Shamozai range. A spring is located in the picturesque gully, north of the sacred area.
The excavation of the first season was limited only to the terraces, which comprise the huge main stupa, and the votive stupas partially uncovered by the treasure hunters. The middle terrace is composed of circular monastery now occupied by the modern village of Gmbatuna. The upper terrace is composed of different group of monastic settlements, caves, viharas and stupas.
The lower zone comprises the main stupa encompassed by the votive stupa and columns bounded by the enclosure wall.
The main stupa stands on a square plinth measuring 17m each side with an offset projection 3.71m long by 3.82m wide for step on the east. The huge stupa is probably the best preserved in ancient Udyana consisting of a dome, upper and three lower drums, resting on a square podium and scole. The structure above the dome comprises harmika and umbrellas, which are now missing.
The stupa is square in plan and consists of base bounding in straight Scotia pattern (H.O 50cm). The podium or the square plinth stands to a height of 3.90m from the top of the base moulding. The top of the plinth is paved with slabs of schist from which project a corine (H. 0.35cm) built in corbelling fashion.
The pradakshina patha around the drum is paved with large stone slabs of schist of various size, from 0.20cm to 0.60cm (in width).
Around the base of the first drum at the four corners the square bases of columns are still preserved indicating that once the stupa was decorated with four columns. Such decorative elements were also noticed at the stupas of Saidu, Najigram and Amlukdara in Swat valley.
The drums of the stupa is cylindrical in shape measuring 04.70m in height. The drum is surmounted by a hemispherical shaped dome (height 04.80m) and 10m in diameter. It is cut all through from the east and a shaft 2m wide sunk down the centre from the top by relic hunters. The stupa is ascended by a flight of twelve steps on the east side leading to the top of the podium. A circumambulation path of schist stone was provided around the base moulding of the stupa plinth. The masonry of the main stupas is executed in diaper.
The main stupa was surrounded by 27 votive stupas of different sizes, square in plan, all composed in the styles of diaper masonry. The floor around these stupas was paved with slabs of schist stone. The upper parts of the votive stupa are missing except votive stupa No.16 and 27 which exist up to the drum. The facing of the plinth built in diaper style in plain in case of some stupas, while stupa numbers 14, 15 and decorated with Corinthian pilasters.
The excavations at Gumbatuna were limited to the northern, southern and western sides. The area in front of the main stupa has yet to be excavated in order to complete the salvage operation at the site. The excavations were limited, as also the sculpture robbers had disturbed the site and removed the antiquities, although a good number of sculptures and an impressive stupa complex were uncovered. These sculptures include Buddda, Bodhisattvas, architectural elements in stone and stucco. The site has yielded no coins which could have helped in providing clue to absolute dating. Nonetheless, the sculptures in stone, stucco and the diaper masonry seem to belong to the early Kushana era. Therefore, it seems probable that the Gumbatuna site flourished during the 2nd century A.D. and lasted until the 7th-8th century A.D.