El Cajon Bay is located in Alpena, Michigan, and is known for its unique karst geology features, including a large underwater sinkhole. This sinkhole is the outlet of an underground stream and never freezes due to the constant flow of warmer water. The bay itself may have been formed by the collapse of the bedrock foundation, with earth cracks common around its rim. The area is rich in natural beauty, featuring untouched northern ferns and the State's wildflower, the Dwarf Lake Iris, which blooms in mid-May.
Visitors can explore the bay during low water levels, allowing them to walk up to the edge of the sinkhole. The surrounding landscape offers a mix of natural and scenic views, making it a fascinating destination for those interested in geology and nature.
The proximity to Lake Huron adds to the bay's appeal, offering a blend of freshwater and terrestrial environments.