Due to the vagaries of history , the details of a first ascents of even many prominent mountains are scanty or unknown ; sometimes the only evidence of prior summiting is a cairn , artifacts , or inscriptions discovered at the top .
The risks for the climbers are often very high , because the way to the top is not known .
The risks for the climbers are often very high , because the way to the top is not known .
Make the sentence simpler: Due to the vagaries of history , the details of a first ascents of even many prominent mountains are scanty or unknown ; sometimes the only evidence of prior summiting is a cairn , artifacts , or inscriptions discovered at the top . Output: