San Bruno Mountain State & County Park, located in the state of California, offers a variety of attractions and points of interest for visitors. This summary has been compiled based on information from multiple independent sources to ensure accuracy.

Reasons to Visit:
1. Breathtaking Natural Beauty: San Bruno Mountain State & County Park boasts stunning panoramic views of the San Francisco Bay Area, Pacific Ocean, and surrounding landscapes. Its diverse ecosystems, including grasslands, forests, and wetlands, provide a haven for numerous plant and animal species.
2. Hiking and Outdoor Activities: The park offers an extensive network of trails, suitable for all levels of hikers, bikers, and equestrians. These trails meander through lush greenery, offering opportunities to explore the park's unique flora and fauna.
3. Birdwatching Paradise: Boasting over 280 bird species, San Bruno Mountain State & County Park is a prime destination for birdwatching enthusiasts. Visitors may spot rare species such as California gnatcatchers, peregrine falcons, and endangered butterflies.
4. Rich Cultural and Historical Significance: The park holds archaeological sites, including ancient Native American settlements, showcasing the area's rich cultural history. Additionally, the park played a pivotal role in the conservation movement of the 1960s, leading to the establishment of the California state park system.

Points of Interest:
1. Summit Loop Trail: This popular trail leads visitors to the park's summit, offering breathtaking vistas of the San Francisco skyline, Golden Gate Bridge, and the Pacific Ocean.
2. Owl Canyon: A hidden gem within the park, Owl Canyon features an enchanting forested area, serene creek, and a variety of wildlife. It provides a peaceful escape for nature lovers.
3. Saddle Loop Trail: This trail takes visitors through beautiful grasslands, showcasing stunning wildflower displays during spring and early summer.
4. Buckeye Trail: Ideal for birdwatchers, this trail winds through dense forests, providing excellent opportunities to observe and identify various bird species.

Interesting Facts:
1. San Bruno Mountain is one of the largest urban open spaces in the United States, spanning over 2,326 acres.
2. The mountain is home to more than 13 endangered and threatened species, including the Mission blue butterfly and San Bruno elfin butterfly.
3. The park's diverse grasslands are remnants of the once-vast coastal prairies that covered the San Francisco Peninsula.
4. San Bruno Mountain was named after Saint Bruno of Cologne by Spanish explorers in the late 18th century.

Best Time to Visit:
The best time to visit San Bruno Mountain State & County Park is during spring and early summer (April to June). This period offers pleasant weather, vibrant wildflowers, and increased bird activity. However, the park is open year-round and can be enjoyed during other seasons as well, each offering its own unique charm.

Please note that it is always advisable to check the official park website or contact park authorities before planning a visit, as conditions and availability may change.