The heart of YOUR metropolis...?

For our next film project we need your help! We are looking for that certain place (district, square, park, hill...) in each of the big metropolises which the most people (inhabitants or visitors) consider to be the 'HEART' of that city. Not the geographical or geometrical or economical center, not a main transport hub, or historic city hall... simply the 'HEART'. So...
Would you please answer us this one question: