On May 1 we saw the launch of Season 4 in Fortnite Battle Royale, and there have been many changes to the map for the new season.
One of those changes is the addition of a hidden bunker / command center that is located under one of Señorío de la Sal's houses.
A Reddit user has posted a video in which one of these new locations can be viewed:
As you can see in the video, one of the ways to access the Command Center in Señorío de la Sal is to place yourself in the hole under the stairs.
Another Reddit post shows another Command Center in a new area, south of Alameda Aullante:
There are likely to be more command centers around the map and possibly a new challenge in the coming weeks to visit them.