Sea/Littoral Caves

Icicles adorn a sea cave along Apostle Islands National Lakeshore, Wisconsin.
Icicles adorn a sea cave along Apostle Islands National Lakeshore, Wisconsin.

NPS Photo by Neil Howk

Sea or littoral caves are formed by the action of waves pounding against rocks that line the shores of oceans and larger lakes. These types of caves are evidence of the enormous power of waves and may be further modified and enlarged by wave-carried sand and gravel.
The following is a partial list of National Park Service units that include sea or littoral caves:
 

Last updated: May 1, 2018