6. The London Eye
Unless your significant other's a ferris wheel enthusiast, there's really no upside to being shoulder-to-shoulder with 20 tourists during your big moment. Also, the Eye's seen more than 5,000 engagements, 512 weddings, and 22 civil partnerships already, so it's possible you won't be the only one in the car with a ring in your back pocket. Lastly, it's a giant ferris wheel.