One of Acapulco's best attractions is the least well-known and also the least expected. High above the city, on the La Cuesta hill, it's a ceremonial and pilgrimage site dating back to 450 BCE to 650 CE, with some wonderfully preserved rock paintings, petroglyphs depicting the story of creation, and the best bird's-eye view of the city spread out beneath you from the site's highest point. It costs around M$350 to get here by taxi from central Acapulco, including waiting time.
Take water with you for the steep slog up between granite boulders, inscribed with human figures and odd human-anchor hybrids. Some depict the participants dancing or wearing ritual masks. The site is located at the confluence of two creeks, suggesting its importance in the worship of Tláloc, the god of rain, who is associated with running water. To reach the most important part of the site, the cave carved with petroglyphs depicting the creation myth, veer to the left. There are explanation boards in English and Spanish. Watch your step, lest you startle a snake dozing in the sun.