Playland-at-the-Beach closed in 1972, and nearly half a century later, it’s difficult to even imagine a huge amusement park along Ocean Beach on the west end of San Francisco. The 9,000-square-foot building is part museum, part indoor carnival, with antique games, pinball machines set on free play and other curiosities. The $10 after-hours event is for visitors ages 18 and older — a kid-free night that is popular with Playland veterans who saw the old park in person.