Annie’s Canyon Trail, formerly known as the Mushroom Caves Trail, is a popular micro-adventure in San Diego that features a slot canyon and impressive oceanic views. It was reopened in 2016 after extensive efforts to remove vandalism from the canyon walls and restore its natural beauty.
The trail begins at the end of North Rios Avenue, and follows the southern perimeter of the San Elijo Lagoon Ecological Reserve for the first half-mile. Despite traffic noise from nearby I-5, this section of the hike is peaceful, and it features wildflowers and views of the lagoon. The area is also perfect for bird-watching: roughly 40% of all North American bird species have been spotted at San Elijo Lagoon. The trail then veers off to the right and comes to a fork. Hikers have the option to bypass the canyon and go directly to the viewpoint or enter the slot canyon via a one-way loop, which ultimately leads to the viewpoint as well.
Although it may be tempting to explore the unique sandstone formations, the area is a sensitive ecological zone. Be sure to stay on the marked trail and follow the Leave No Trace principle. The slot canyon ends rather abruptly, and a climb up a short ladder is required to get out. At the top, hikers are rewarded with stunning views of San Elijo Lagoon, the ecological reserve, and the Pacific Ocean.