Istanbul sits across two continents, split by the Bosporus, and the point here is in the old peninsula on the European side, where the Golden Horn meets the strait. The city was Byzantium, then Constantinople, capital of the Roman Empire in the east for over a thousand years, and from 1453 the seat of the Ottoman sultans. The layers show everywhere. Hagia Sophia, finished in 537, still has the most astonishing dome in the world, hung as if from nothing over a vast interior, and nearby the Blue Mosque, with its six minarets and cascade of domes, stands across a garden, built in the early seventeenth century as an Ottoman answer.
The area also holds Topkapı Palace, where sultans lived above the Bosporus, the Basilica Cistern, an underground reservoir with a forest of columns, and the Grand Bazaar, a covered labyrinth of some four thousand shops, selling carpets, ceramics, gold and lamps. At Eminönü, on the water, ferries leave for Kadıköy and the Asian side, and fishermen sell sandwiches of grilled mackerel from boats that rock at the quay. The city is loud, dense and exhausting, and also one of the most rewarding in the world to walk in.
Riding in Istanbul requires a calm head. The traffic is heavy at almost any hour, the lanes are fluid, and delivery riders on small scooters weave through gaps with confidence. The bridges across the Bosporus and the motorways are fast and busy, and the cobbled streets of the old town are steep and slippery when wet. The best time to move is early on a Sunday, when the city is quiet, and a short ferry ride is often a better way to cross than the bridge. In winter, rain and cold wind from the Black Sea are common, and spring and autumn are the pleasant seasons.
Fuel is easy, with stations throughout the city, though they are less common on the old peninsula, and parking for a motorcycle near the sights is limited, so a secure garage is useful. After the sights, a plate of fish at a small meyhane in the back streets, with a glass of raki and a dish of mezes, is the right way to finish a day, and tea in a tulip-shaped glass will arrive without being asked.