This is the 3626th most frequent Spanish word.
minas
"Minas" in English means "mines."
Here, 'minas' refers to mines, specifically places where minerals, coal, or other valuable substances are extracted from the ground.
Las minas de carbón son esenciales para la economía local.
The coal mines are essential for the local economy.
In this context, 'minas' still refers to mines, though in a more fictional, treasure-hunting story context rather than a literal industrial one.
Las niñas jugaron a ser piratas buscando minas llenas de tesoros.
The girls played at being pirates searching for treasure-filled mines.
Here, 'minas' is short for 'minas terrestres', meaning landmines, which are explosives placed on or just under the ground.