An iron shore is a type of coastal feature, or geological formation of Pleistocene reef material in tropical waters.
The iron shore or Ironshore in the Caribbean is a geological feature.
In tropical regions and most particularly in the Caribbean, "ironshore" describes a coastline that is characterized by Pleistocene reef material, which has been shaped by solution dissolution instead of abrasion.
This zone of solution also extends from just below the mean tide level that is inland, as far as storm waves can throw the seawater.
The term "ironshore" is also a local name that refers to the physical appearance of the coast and not it's chemical composition.
Examples of the ironshore are parts of South Florida, Cuba, Bahamas, Roatan and the Cayman Islands.
The ironshore formation is often formed of poorly lithified limestones which commonly also contain numerous and well preserved fossils.
Ironshore is basically the type of rock that forms along the coastline in some Caribbean islands (notably Cayman).
If they say ironshore beach it often means they don't have a sandy beach, so you will be oceanfront, but not beachfront.