Images with HiRISE show gullies which were once thought to be caused by flowing water. Penticton is famous with Mars geologists because evidence for recent flowing liquid was found there. The Mars Reconnaissance Orbiter discovered changes on the wall Crater. (wikipedia entry)
A crater is a circular depression likely created by an impact event. On Mars large craters are named after deceased scientists, writers and others who have contributed to the lore of Mars. Small creaters (less than 60km) are named after small towns and villages.