King Street, the hub of Old Alexandria, is loaded with colorful (and surprisingly affordable) boutiques, rockin’ restaurants of all kinds, bakeries and bookstores. So, while the red and black King Street Trolley is, in fact, a bus — just go with it. Kids don’t need an actual trolley with cables overhead to be happy. The King Street Trolley begins at the King Street Metro and travels down to the waterfront. Be assured that the trolley arrives like clockwork every fifteen minutes, is absolutely free for all riders and collapsed strollers are welcomed.