Who the Trung sisters were
Trưng Trắc and Trưng Nhị led an uprising against Han Chinese rule in 40 AD. They ruled for about three years before the revolt was put down. Today they are national heroines, and many streets, schools and a whole Hanoi district carry their name.
The temple is also called Đền Đồng Nhân, after the area where it stands. It was first founded in the 12th century on a sandbank of the Red River. River erosion later forced a move, and the temple was rebuilt on its present site in the early 19th century.
What to look at
Pass through the gate into a calm courtyard with old trees and incense burners. The main hall holds statues of the two sisters, dressed in ceremonial robes and surrounded by offerings, carved panels and lacquered boards with Chinese characters.
Take your time with the details: the roof decorations, the guardian figures and the worshippers' offerings of fruit and flowers. Local people come here to pray, so you see a working temple rather than a museum piece.
When to go
Mornings are usually the calmest and coolest time to visit. The temple gets busier around Tết and on the first and fifteenth days of the lunar month, when locals bring offerings. Those days are lively and colorful, but expect more incense and less space.
Combining it with nearby sights
The Vietnamese Women's Museum is about 1.4 km away and pairs naturally with this visit, since both tell stories of Vietnamese women. The National Museum of History is a similar distance. You can then continue to Ngoc Son Temple and The Huc Bridge on Hoan Kiem Lake, about 2.1 km away, or to Quán Sứ Temple, about 1.8 km away.