The Big and Obvious Ride was Phineas and Ferb's invention in "Don't Even Blink". They only built it on Candace's request and to see where it would go after they were done it. As Linda came home, Dr. Doofenshmirtz's Invis-Inator continued to make it invisible then make it visible. When Candace figured out it was invisible, she ran to the garage and got an orange paint can. Doofenshmirtz's Disintegrator then destroyed the invisible ride, and Candace had to clean up the mess she made with the orange paint.
Big Ben Water Slide
Chez Platypus (restaurant)