Dolmen D1 is a portal grave located in the Dutch province of Drenthe. The dolmen is located near the town of Steenbergen. The town of Steenbergen is named after the local dolmens, as the name literally translates to “Stone Mountains”. Dolmen D1 is close to a paved road and it is easily accessible, thanks in part to the nearby parking lot.
The dolmen is attributed to the funnel-beaker culture and lies against a slope of sand. The dolmen is well preserved and consists of 12 supporting stones, 6 capstones, and 2 keystones. The gate stones consist of 2 supporting stones and 1 capstone.
The dolmen is 11.6 meters long and 3.6 meters wide. The basement content has never been investigated.