Lhuentse Dzong is a dzong and Buddhist monastery in Lhuentse District in eastern Bhutan. It lies on the eastern side of the Kuri Chhu and is suspended on a spur at the end of a narrow valley.

The Dzong was initially known as Kurtoe in the then-isolated Lhuentse District. It is the ancestral home of the House of Wangchuck (Dasho Jigme Namgyal was born there in 1825).

While Lhuentse Dzong’s geographic coordinates are in eastern Bhutan, its cultural roots are central Bhutanese. Initially road traffic connected it to Mongar, the approach was through a trade route crossing Rodang Pass.

The Dzong is situated in the Kuri Chhu valley, which is part of the Lhuntse district. The Kuri Chhu is the chief river that has formed the beautiful valley with high peaks and steep hills. Kuri Chhu is a branch of the Manas River system, which is the major river of Bhutan and a major tributary of the Brahmaputra River that drains maximum of Eastern Bhutan.

The road from Mongar to Lheuntse Dzong is a 3 hours drive over a distance of 77 kilometres and 63 kilometres from its junction at Gangola. The approach to this Dzong is over a flag-stone-paved path over the steep cliffs.

According to one legend, Khedrup Kuenga Wangpo, son of Tertön Pema Lingpa was allocated to find a ridge resembling the trunk of an elephant. He found one opposite Baeyul Khenpajong and meditated there. This location came to be well-known as Kurtoe Lhuentse Phodrang.

The monastery was initially well-known by Pema Lingpa's son Kuenga Wanpo in 1543, although it wasn't until 1654 that the Trongsa penlop (governor), Minjur Tenpa, made a formal dzong here after winning a battle and named it Lhuentse Rinchentse. The dzong was later restored in 1962 and again among 1972 and 1974. The historic importance of Lhuntse Dzongkhag is on account of its recognized link as the ancestral home of the Wangchuck Dynasty. Lhuentse town is the administrative capital of Lhuentse District, besides the Lhuentse Dzong. Currently there are 100 monks who reside here.

The dzong comprises five temples, three of which are in the central tower and are devoted to Padmasambhava. The dzong also contains a Gonkhang, which is devoted to Mahākāla, and a temple devoted to Amitāyus, the Buddha of Infinite Life. The ground floor also has a temple devoted to Avalokiteśvara. The Kunre, the assembly hall for the monks, is situated on the upper floor.

The dzong has suffered grave damage through an earthquake measuring 6.1 on the Richter magnitude scale that hit eastern Bhutan on Monday, 21 September 2009. Many other monasteries in the region also suffered serious damage.

Trashigang Dzong (The Fortress of the Auspicious Hill) is one of the largest dzong fortress in Bhutan, located in Trashigang in Trashigang District of Bhutan. The fortress was built in 1659 to defend against Tibetan invasions. The dzong hosted a monastic community besides acting as the central administrative center of the Trashigang District, before they were shifted due to the ongoing restoration.

The fortress was constructed in 1659 atop a ledge with steep cliffs on three sides, overseeing the Drangme Chhu and Gamri Chhu rivers. The structure of the dzong was forecasted by Ngawang Namgyal who ordered the Penlop (Governor) of Trongsa, Chhogyal Minjur Tempa to put down native chieftains and construct the dzong. According to legend, the view of the Dzong scared the Tibetan army which retreated while commenting that the Dzong was a "Sky Dzong and was not on the ground". The dzong was further expanded by Gyalsey Tenzin Rabgye between 1680 and 1694 and by Dzongpon Dopola in 1936. The dzong was blessed and named as Trashigang by Dudjom Jigdral Yeshe Dorje. After the 1962 Sino-Indian War, Bhutan permitted Indian soldiers returning home to pass through Eastern Bhutan. However they were compulsory to deposit their rifles at the armoury in the Dzong, and continue through Bhutan unarmed. The rifles lie in the Dzong to this day. The dzong revels the four day long Trashigang Tshechu festival every year, with around 1500 people participating the celebrations on each day.

The dzong developed wide cracks as a result of the 2009 Bhutan earthquake, whose epicenter was 10 miles (16 km) away from the dzong. A partnership between World Monuments Fund, Prince Claus Fund and the Bhutan Foundation was contributory for help in emergency repairs at the dzong. In February 2014, the Government of India allotted Nu.190 million for renovating the dzong. The renovation works are expected to be completed by June 2018, while the costs have risen to Nu.227.5 million. A drasha (monk hostel) for 50 monks, besides a tshokhang (dining area) are built outside the dzong's premises for safety and health reasons. The government is also recruiting local unemployed youth to construct the dzong, and will be using locally obtained materials in the construction, counting timber mostly from Bumthang and stones from Chazam. The Trashigang district administrative offices have been temporarily relocated to the Trashigang Middle Secondary School while the clergy were moved to a school in Samkhar Gewog, about 10 km away from the dzong.