San Ġwann is a recent development which grew in the 1960s from several smaller communities. It is a sought-after residential area lying just inland from Sliema. So rapidly have shops and cafes sprung up here in the past decade, that San Ġwann has become a busy commercial centre in its own right. Tucked away in the residential area are some of Malta's enigmatic cart ruts. Thought to date back to the Bronze Age, these curious parallel grooves cut in the rock have defied clear explanation. They may have been used for some sort of prehistoric vehicle, perhaps for the carrying of soil. San Gwann is the site of a remarkable troglodyte church, tal-Mensija Chapel, dating back earlier than the 15th century. Its origins are shrouded in mystery and legend. Pope Leo XII granted the small church privileges in 1879 and it remains to this day a place of devotion.