Possible Clues:

• Pleasant to look at
• Attractive
• Good to look at
• Not difficult covering London landmark, pleasant to look at
• Pretty nervous riding Millennium Wheel when first couple gets off?
• Nice to look at
• Visually pleasing
• Attractive drug like that attracts you more than once
• Simply regarded as attractive?
• Wild one, say, with a double you that's good to look at