Score 86/100 · Order: Slot canyon loop, 2 miles · Free
Annie's Canyon squeezes through a sandstone slot barely wider than your shoulders before opening onto an overlook of San Elijo Lagoon. It is short, strange, and unlike any other trail in the county. Weekday mornings are far quieter.
Local tip: The slot is one-way and tight; skip it if you're claustrophobic or carrying a large pack.