The Church of St. Nicholas in Densuș is among the oldest and most unusual sacred buildings in Romania, and almost certainly the country's oldest still-used Orthodox church.

It likely dates from the 13th Century, although the original structure on that site may have been built much earlier. Since no written documentation of its founding survives, its exact age is disputed. Theories about the structure's origins abound, including that it was built on the site of a pagan temple, or served as a mausoleum for a Roman general. The Late Romanesque construction is curiously piecemeal, giving the impression that it was built in several stages, also incorporating stone from the nearby ruins of Roman Sarmizegetusa (Ulpia Traiana).

The 15th Century interior murals were recently renovated with the help of the Ambassador Michael Guest and the U.S. Embassy in Bucharest.