Learn, play, and explore at the interactive science museum The Exploratorium, located right on the pier in San Francisco! It usually costs around $30 to get in, but this Sunday, the Exploratorium is having a rare "pay what you wish" day. This means you can pay the museum whatever you can afford to get in, even if that means you can't pay anything! So even if you're on a budget, you can still go check it out for free! The Exploratorium always has some extra activities and lots of fun planned. It's free/donation based from 10 a.m. until 5, but plan to get there EARLY - they almost never have free/"flexible admission" days, so it will be packed! Be prepared!