I've been sitting on this idea for years.

Growing up in South Florida, I've always been aware of sea level change. Due to a combination of human activity and natural processes, the sea level today is not going to be the same as it will be in the coming decades.

For people in coastal areas all over the world, this means migration.

Humans have lived in Florida for at least 20,000 years. During that time, the sea level has risen considerably. What are now the Florida Keys were once part of the mainland, just as parts of the mainland will soon be new Florida Keys.

The native peoples all over the Americas had a habit of building mounds. Archaeologists today are not entirely sure what these mounds were used for, but they have some things in common. For one, many of them were built on floodplains. There are mounds to the south of Lake Okeechobee, at the "floodgates" of the Everglades headwaters. There are mounds along the Mississippi River in areas which are prone to flooding, where today, towns get washed away every few years or so. Mounds were often (but not always) built from local materials, and sometimes took the form of pyramids. Ancient pyramids today, long since abandoned, resemble green hills all over the Yucatan peninsula.

One great application for mounds is that, during times of flooding, it gives you a piece of dry ground to stand on.