The southernmost mountains of California are the Peninsular Ranges, which are east of San Diego and continue into Baja California (Mexico) in the Sierra San Pedro Martir. The Peninsular Ranges contain the Laguna Mountains, the San Jacinto Mountains, the Santa Rosa Mountains, the Santa Ana Mountains and the Palomar Mountain Range, notable for its famous Palomar observatory. San Jacinto Peak's eastern shoulder has a cable tram that runs from the desert floor to nearly the top of the mountain where riders can set off hiking or go cross-country skiing.