Things to do in San Bernardino County are listed by cities below such as San Bernardino, Ontario, Fontana, Rancho Cucamonga and Rialto. San Bernardino County is located in southeast California, east of Kern and Los Angeles Counties and northeast of Orange County. This large county offers many stunning locations and places of interest. The Mojave National Preserve is located in the Mojave Desert of San Bernardino County. In Mojave, there are volcanic formations like the famous Hole-in-the-Wall and the Cinder Cone Lava Beds. The Marl Mountains, Kelso Dunes and Cima Dome are also stunning natural features that the preserve showcases. The northern portion of Joshua Tree National Park, a famous hiking and rock climbing playground, is accessible from the Twentynine Palms area of the county. The San Bernardino National Forest is another proud San Bernardino natural marvel, as it spans over 800,000 acres and is a beauty to behold. The San Bernardino Mountains include wonderful resort areas including Big Bear Lake and Big Bear City, Lake Arrowhead, and even "Arrowbear Lake" among others, all easily accessible from the LA area. If you stop by the National Forest, make sure to see Bonita Falls, touted as the forest's best waterfall. The desert town of Barstow is worthy of a long stopover when passing through this vast region.