My #bandofsketchers prompt today was ‘substantial’, I can remember seeing photos of standing stones with a flat stone on top. This was done from memory. I didn’t even know what they were called so had to look it up. Felt pen drawing. Wikipedia says: dolmen (/ˈdɒlmɛn/) or portal tomb is a type of single-chamber megalithic tomb, usually consisting of two or more upright megaliths supporting a large flat horizontal capstone or “table”. Most date from the early Neolithic (4000–3000 BCE) and were sometimes covered with earth or smaller stones to form a tumulus (burial mound). Small pad-stones may be wedged between the cap and supporting stones to achieve a level appearance. In many instances, the covering has eroded away, leaving only the stone “skeleton”.