Greater Springfield boasts the second-largest concentration of institutions of higher learning in New England.
Companies moving to the site are served by the second-largest concentration of hotel rooms outside downtown.
Islam is the largest non-Christian religious group, with 100,185 members, the second-largest concentration of Muslims in Canada.
The Criel Mound is part of the second-largest known concentration of Adena mounds and circular enclosures.
The county has the second-largest concentration of muck soil in the nation, after the Everglades in Florida, and the largest area of such land used for onion crops.
The Guadalajara metropolitan area, which includes eight municipalities, had a population of 4,095,853, the second-largest urban concentration in Mexico after Mexico City.
But it is especially troubling in Westchester, which has the second-largest concentration of state and independent colleges and universities in the state.
This was the second-largest concentration of Puerto Ricans in the Northeast, behind only Holyoke, Massachusetts (source: 2010 census).
The Rattlesnake Canyon area is home to the world's second-largest concentration of natural arches (after Arches National Park).
Bridgeport and its suburbs have the second-largest concentration of Hungarians in the United States (after Cleveland), making Connecticut a popular destination for newer immigrants.