On this page there’s 7 highlights (view in Baymard Premium) outlining what Costco are doing right and wrong.
(Tip: use the arrows above or on your keyboard to navigate all 106 top-level navigation examples.)

The screenshot was taken on October 31, 2013 and depicts Costco’s Top-Level Navigation. In total, we’ve reviewed 65 of Costco’s page designs. To see them all, visit the full Costco UX case study.