<prompt> Translate the following text to EnglishHuko chini ya ardhi kuna mlango unaoitwa Lapis Niger, ambao ni mlango wa marumaru uliotengenezwa na Kaisari Yulio na ambao unadhaniwa kuwa kaburi la Romulus, mwanzilishi wa jiji hilo.  <response>: Steps nearby lead underground to the Lapis Niger, a black marble pavement laid by Julius Caesar over the presumed grave of Romulus, the citys founder. 