Pietroasele is a commune in Buzău County, Romania, known for its vineyards. The name means "the rockies". The commune is composed of six villages: Câlţeşti, Clondiru de Sus, Dara, Pietroasa Mică, Pietroasele and Şarânga.

Ruins of a third-fourth century AD Roman castra and thermae were discovered in the area in the 1980s.

The Roman fort of Pietroasa de Jos, well beyond the Danubian Limes and near present-day Moldavia, would seem to have been occupied in the fourth century A.D.

It was connected to bridge-head forts (Sucidava, Barboşi, and the unlocated Constantiniana Daphne) along the left bank of the Danube river.

Near this Roman fort, built by Constantine I when he created the Constantine Wall of the Limes Moesiae probably around 330 AD, researchers have found even a small thermae building in the 1980s.

The Roman fortification (124 m x 158 m) was built in an area where was present the Culture of Pietroasa.. The wall was 2.7 meters thick. There were discovered some stamped briks of legio XI Claudia Pia Fidelis from Durostorum, specific to Traian ages.Bricks stamps with LEG XI CL ANT and LEG XI CPF. Nowadays there is a small museum on the former site of the castrum.