It looks like someone added one too many top level pages to the main navigation. Here are a few quick fixes...
1. Remove one of the top level pages and add a link to it via a call out or something
2. Reduce the size of the "spacer" image to something smaller
BTW: I see that the site is built on Sitefinity 3.7 SP1 - Community Edition, I believe that there is supposed to be a Sitefinity logo on there somewhere ;)