Eat lunch somewhere you can watch something happen

Cranes swinging, ferries docking, pallets coming off a truck — the city runs a free matinee every lunchtime and almost nobody watches it. Find a dock, a square, a station concourse, or a building-site fence with somewhere to sit. Buy lunch from the closest place that sells anything and stay until the show gives you one good moment. The sandwich doesn't have to be good; the seat does.