Which of these is a mound-like or hemispherical structure that is used as a place of meditation?

A stūpa (Sanskrit: स्तूप, "heap") is a mound-like or hemispherical structure containing relics (such as śarīra – typically the remains of Buddhist monks or nuns) that is used as a place of meditation. A related architectural term is a chaitya, which is a prayer hall or temple containing a stupa.

In Buddhism, circumambulation or pradakhshina has been an important ritual and devotional practice since the earliest times, and stupas always have a pradakhshina path around them.

Stupas may have originated as pre-Buddhist tumuli in which śramaṇas were buried in a seated position called chaitya.

Some authors have suggested that stupas were derived from a wider cultural tradition from the Mediterranean to the Indus valley, and can be related to the conical mounds on circular bases from the 8th century BCE that can be found in Phrygia (tomb of Midas, 8th c. BCE), Lydia (such as the tomb of Alyattes, 6th c. BCE), or in Phoenicia (tombs of Amrit, 5th c. BCE).