Take the time to discover the some of the stone carvings adorning old buildings and brownstones when you are walking around in the city.  I like to photograph gargoyles when I am able to find them. They are not just pretty things, their original function on century old buildings was to act as rain spouts.  Like some kind of markers, the stone carver craftspeople and artists who created these urban stone tribes of people, saints, serpents, dragons where saying - "I was alive once and left something of myself here."