Congaree National Park

About 20 miles southeast of Columbia, South Carolina, Congaree protects the largest remaining old growth bottomland hardwood forest in the United States. Its floodplain grows some of the tallest trees in the eastern US, including bald cypresses more than 500 years old. For about two weeks each year, thousands of fireflies blink in perfect unison, one of the few synchronous displays in North America. Late May to early June is the time to see it.