Click on images automatically leads to lightbox-gallery

Example page from my website: http://www.jongvld.be/jongvld/wie-zijn-we/

Every image is clickable and shows by default a lightbox-gallery of all the images on the current page. This is verry annyoning. On some pages, i actually want images to link to an URL, but for some reason the lightbox gallery-function always prevails.

I tried everything: setting the default image link to “none”, changing it for every image individually, installing no-click plugins etc. Nothing seems the work.

Any ideas? Thanks!