D51 Noord Sleen
D51 is almost a twin to D50 because they are only 100 metres apart. D51 used to be a medium sized hunebed with 7 capstones, but 4 of them have been robbed in the past. D51is an example of a passage-grave with a long passage consisting of 4 passage sidestones (other examples are D15, D26, D27 and D53). Three are still there. The fourth is marked by an concrete imprint in the soil.