Cayce lies mostly across the Congaree River from the state capital of Columbia, with a newly annexed section on the Richland County side awaiting development. Because both it and the neighboring city of West Columbia share road names and schools, they are sometimes referred to jointly as "Cayce-West Columbia". However, they are politically separate cities.
The Congaree River has always played a dominant role in Cayce's development. Cayce and other local governments jointly developed the Riverwalk along the Congaree, which provides walking, jogging, and nature observation opportunities. Development on both sides of the river is an important factor driving the city's economy.