Where do I place packages inside my catkin_ws folder?

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Hi,

I have a pre-existing package called ORB-SLAM. It has a folder for Data/Thirdparty/cmake_modules/include/src folders so I am assuming that it's a package. I think it was written on the older rosbuild version since it has a manifest.xml file instead of a package.xml file. I am pulling this from github: https://github.com/raulmur/ORB_SLAM

I've also just finished creating a catkin workspace with this tutorial: http://wiki.ros.org/catkin/Tutorials/...

Where am I supposed put this ORB-SLAM package? Should I put it inside the catkin_ws folder and if so should I put it inside its src or devel folder? A link on how to do this would be super great. Thanks.