Summary: Rory has never seen so many species of alien all in one place.
Rory looked uncertainly around the vast room. Everywhere he turned there were aliens, thousands of individuals, and more different kinds than he'd ever imagined existed. Some were more than twice his height; he didn't know whether to be impressed or terrified.
"I feel like I've accidentally walked into a sci-fi convention," he muttered to Amy, then raised his voice to address the Doctor, walking a few feet ahead of them. "What is this place?"
"The biggest spaceport in the universe!" the Doctor explained. "Almost everyone passes through here at one time or another."