The portals generated in cape comes from 2 places
The exports folder
And the terrains folder.
In "most" cases unless it's map pack downloads, 1 .fhm file represents 1 portal in the exports folder. So you can delete the ones you don't want there, or delete exported maps you already have in the terrains folder.
The terrains folder has all the "map folders" that is the actual maps you have made. In order to get rid of them you have to remove the whole map folder. You can also enter the map maker, load one of the maps in the terrains folder, and then remove the checked box "Has portal" Then save it, and the portal in cape will automatically get removed, but you will still have your map in the folders.
If you made a map called "Hurrmurrmap" there will be a folder in terrains called "Hurrmurrmap" as well.
