Create a 3000x2000px minimalist flat illustration featuring a collage of iconic London landmarks, including the London Eye, Big Ben, Tower Bridge, and St. Paul's Cathedral. Use a limited color palette of three pastel colors and maintain a simple, geometric style. The illustration should evoke a sense of whimsy and be suitable for use as a book cover.

The image shows a vibrant London skyline with Big Ben and the London Eye in the background. We can see a boat on the water, a bridge, trees, buildings, flags, and birds flying in the sky. The image is animated, giving it a lively feel.