We walked off onto the Isle of Portland – an island that isn't quite an island, tethered to the mainland by Chesil Beach, that remarkable 18-mile tombolo of pebbles that looks like a giant's necklace from above. The moment we stepped ashore, I felt the weight of history beneath my feet. This limestone peninsula has been quarried since Roman times, and the very stone I stood on might share DNA with St Paul's Cathedral's dome, standing proud across the water in London.

Our first stop was Portland Castle, built between 1539 and 1540 on Henry VIII's orders when he feared invasion from Catholic Europe. Standing in its courtyard, I imagined Tudor soldiers scanning the horizon for enemy sails – the same horizon I watched cruise ships glide across today. The harbour spread out before us, once a major Royal Navy base, its deep waters still and vast. In 2012, these same waters hosted the Olympic sailing events, bringing the world's eyes to this ancient coast.

The views from the Olympic Rings viewpoint took my breath away – Weymouth Bay stretching north, the English Channel opening south and east, endless blue meeting endless sky. Then we drove to Portland Bill lighthouse, standing sentinel at the island's southern tip since 1906, though earlier lights have warned mariners since 1716. At noon, we watched waves explode against the rocks while guillemots wheeled and called overhead, their cries mixing with the wind that never stops here.

We went fossil hunting along the beach, treading carefully on this UNESCO World Heritage Site – part of the Jurassic Coast since 2001. I found ammonites and belemnites just lying there, 180-million-year-old spirals and bullet shapes that once swam in warm, shallow seas. Each one felt like holding a whisper from the Jurassic Period, when giant marine reptiles ruled these waters and Portland was somewhere else entirely, drifting slowly north on tectonic currents.

We had lunch at the Crab House Café overlooking the water – whole Portland crab cracked tableside, so fresh it tasted like the sea had waved goodbye only moments before. The meat was sweet and delicate, nothing like the heavy, oversalted seafood you sometimes get at tourist spots. The pros: Portland feels like the edge of England in the best way – raw, windswept, beautiful, layered with stories. The cons: windy (always, relentlessly), but that's exactly why the views exist and the fossils keep tumbling free.