Petrarch is a crater on Mercury at latitude -30, longitude 26.5. It is ~170 km in diameter. This crater is located within the distorted terrain on the opposite side of the planet from the Caloris Basin. (wikipedia entry)
A crater is a circular depression likely created by an impact event. On Mercury they are named after deceased artists, musicians, painters, and authors who have made outstanding or fundamental contributions to their field and have been recognized as art historically significant figures for more than 50 years.
Image Source. Marker locations are approximate and may not always appear to align with image on map.