Manhattan is 13 miles or 21 km long and around 2 miles/3km across. Places are clustered, sort of.
MIDTOWN includes the Public Library main branch, Grand Central, Empire State Building, Macy’s, Bryant Park, Times Square, Rockefeller Center and St. Patrick’s.
CENTRAL PARK is north of Midtown.
THE FINANCIAL DISTRICT is close to the Statue Of Liberty and Staten Island ferries, National September 11 Memorial, Wall Street, South Street Seaport, the Brooklyn Bridge, and it’s fairly close to Chinatown.
My company does walking tours that may go through up to 3 districts in a tour:
SoHo, Little Italy and Chinatown.
Brooklyn Bridge, Brooklyn Heights, and DUMBO.
Brooklyn Heights, ferry boat to Wall Street, and African Burial Ground.
Grand Central, Saint Patrick’s, Rockefeller Center, and Times Square.
Brooklyn Heights, ferry to Manhattan, Murray Hill, and end at customer’s choice of Grand Central or Empire State Building.