Possible to internally deactivate a site that is used in ajax thought?

Hello, 
i have a little custom code made specifically for a gallery lightbox. 
This little ajax script is leading to https://www.lonniwong.com/portfolio and all the sources are prepared under this path.

Is it possible to deactivate or make this direct URL path not accessable, but instead only be used as a true gallery lightbox on the main page?

Thank you for any tips!