Unique Things to Do in San Francisco

A unique acoustic sculpture built in 1986 by Exploratorium artist Peter Richards — 25 PVC organ pipes and stone from the demolished Laurel Hill Cemetery create music from bay waves. Located at the tip of a jetty near the Golden Gate Yacht Club with panoramic views of Alcatraz, the Golden Gate Bridge, and the city skyline. Visit at high tide for the best sounds; at low tide the pipes are mostly silent. Full moon tides amplify the acoustics. A 1.8-mile trail connects to Crissy Field.

One of the world's largest privately owned collections of coin-operated mechanical machines, with 300+ vintage arcade games, penny arcade machines, player pianos, and animated dioramas dating from the 1800s to the 1990s. Free admission — machines cost a quarter or fifty cents each, so bring $5-10 in coins. The oldest machines in the back (fortune tellers, execution dioramas from the early 1900s) are the most fascinating. The 'Laffing Sal' figure at the entrance is an SF icon. Open 365 days a year.

A stunning community mosaic art project featuring 163 tiled steps depicting a flowing sea-to-sky design with sea creatures, flowers, and stars, completed in 2005. Best photos before 10am or after 4pm when the steps are empty. Take the N-Judah to 15th Ave & Judah and walk uphill, or have your rideshare drop you at the top and walk down. The tile can be slippery — use caution. Combine with nearby Grandview Park for panoramic city views. In a quiet residential neighborhood, so keep noise down.

Two steep concrete slides built into a hillside, designed by a 14-year-old in the 1960s and opened in 1973. Choose the red slide or the yellow slide (steeper and faster). Bring cardboard to sit on — without it, the concrete friction slows you down and ruins your clothes. Locals grab flattened boxes from nearby stores. The slides are steeper than they look and the yellow one is legitimately thrilling. Hidden in a residential area and easy to walk right past.

The world's only free public museum dedicated to the science of sight, operated by the American Academy of Ophthalmology. Houses 38,000+ artifacts including rare books, antique ophthalmic instruments, optical illusions, and immersive exhibits about how vision works. Most tourists walk right past on the way to Ghirardelli Square. Far more interesting than it sounds — the historic surgical instruments and perception exhibits are genuinely fascinating.