<prompt> Translate the following text to EnglishKwenye ukingo wa magharibi wa mto huo, katika eneo la jangwa, kuna makao ya watawa wa Kikopti ya St. Simeon ya karne ya saba, ambayo sasa ni magofu, na Mausoleum ya Aga Khan 1877-1957, kiongozi wa kiroho wa madhehebu ya Waislamu wa Ismaili.  <response>: On the west bank of the river set in a desert landscape is the seventh-century Coptic monastery of St. Simeon now sadly in ruins, and the Mausoleum of the Aga Khan 1877 1957, spiritual leader of the Ismaili Muslim sect. 