Of striking natural features--self-created objects of veneration, as the Hindus call them--many kinds are found. There are chasms from which issue mysterious vapours, stimulating prophecy, such as Delphi, or Jwala Mukhi, sacred to Hindus and Sikhs, or the Grotta del Cane, near Naples. Caves with their dreadful gloom inspire a sense of supernatural presence. Such are the cave of Trophonius in Boeotia, St. Patrick's cave in Ireland, the grotto of Lourdes, Mariastein near Basle, and the great fissure of Amarnath in Kashmir, with its icy stalactite which is the special object of worship. Some of these add to their sanctity by difficulty of access: St. Patrick's cave is on an island in Lough Derg; Mariastein lies over the edge of a steep cliff; Amarnath is hidden among lofty mountains at 17000 feet above the sea. Enormous stones, too, are apt to acquire holiness, arousing interest by their vast mass; as though they could hardly have been brought into independent existence, detached from the great earth, without some direct intervention of divine power. Such are the stone at Delphi, or the great rock, now enshrined in a Muhammadan mosque, which no doubt caused men to go up to Jerusalem in Jebusite days, before Israel came out of Egypt. (It is thought by pious Muhammadans to rest in the air without support; their tradition being that at the time of Muhammad's ascension into heaven this stone, which was his point of departure, sought to accompany him but was detained by an angel. To the Hebrews it was sacred as the rock on which Abraham was ready to offer Isaac; and also as a stone which kept down within the earth the receded waters of the Flood.) Meteoric stones have a sanctity as having fallen from heaven: for example, the _lingam_ of Jagannath at Puri, and the famous black stone at Mecca. Wells also, for obvious reasons, tend to attract worship. Of places inaccessible to which pilgrims toil, some are the sources of rivers, like Gangotri, whence springs the Ganges: others are islands, such as the Iles de Lerins off Cannes, Iona and Lindisfarne, or many off the West coast of Ireland: or distant headlands, like the Spanish Finisterre, or Rameshwaram, the extreme southern cape of the Indian peninsula. More numerous are those which lie high up on mountains or above precipitous rocks; such as the many peaks of Sinai, the lake on Haramuk in Kashmir, the cliffs of Rocamadour in Central France, which Piers Plowman mentions,[33] or the grey cone of Athos. In a mild form such places may frequently be seen, in the pilgrimage churches and chapels which crown modest eminences beside many villages and towns of Catholic Europe: akin no doubt to the high places and hill-altars where lingered the heathen worship that the Israelite priests and prophets were continually trying to exterminate.