Megaliths are large, ancient stones used for construction and religious purposes. Synonyms for megaliths include monoliths, standing stones, dolmens, and cromlechs. Monoliths refer to single, large stones standing upright, often used as landmarks or monuments. Standing stones are similar to monoliths but can also be grouped together in circles. Dolmens are ancient structures made of megaliths, typically used as tombs or burial chambers. Cromlechs are also ancient rock formations typically used for religious or ceremonial purposes. These synonyms illustrate the diversity and importance of megaliths in ancient times, and their continued fascination and mystery today.