Magento

You can add Categories so that they are not under the Default Category. They will be at the same level as Default. However, only Categories under Default will automatically appear in the Navigation Menu. If a Category is not under Default, you will need to create some other way for your customers to get to that Category.

Do you know how to get to that Category?

In Admin go to System->Manage Stores. Then Click “Main Website Store”. Then from the the dropdown of root category select your category, Then save.