Paddle between black lava rocks on the northwestern tip of Madeira. These crystal-clear paddling spots were formed when volcanic lava bubbled furiously into the sea and settled to form a natural rock pool. Despite being tamed for swimming purposes (with added steps, and a few perky parasols), the natural waters are strikingly superior to any hotel pool we've encountered. Head out in the morning, pay the £1.25 entrance fee and flop on a sun-drenched sun lounger for a few sizzling hours by the pool. It's the perfect place to perfect your crawl (read: cool off between tanning sessions).