Few cities have grown inside a palace, but Split did exactly that. Around the year 300 the Roman emperor Diocletian, born in nearby Salona, built himself a vast fortified retirement residence on the shore of the Adriatic, a rectangle of walls, towers and gates. When Salona was sacked in the seventh century, refugees moved into the palace, and over the following centuries they turned its halls and corridors into streets and houses. The result is a living old town where medieval and Renaissance homes lean on Roman walls and washing hangs between ancient columns.
The heart of it is the Peristyle, a colonnaded courtyard in front of Diocletian's mausoleum, which became the cathedral of St Domnius, named, rather pointedly, after a bishop martyred under the emperor's persecutions. Its bell tower gives a wonderful view over the roofs and harbour. The cellars beneath the palace, used for centuries as a rubbish dump and therefore beautifully preserved, show the plan of the imperial rooms above. Outside the walls, the Riva promenade is the city's living room, and the wooded Marjan peninsula offers shade and swimming coves.
Riding into Split is a test of patience. The approach roads from the motorway and along the coast are busy, with heavy traffic, tight junctions and scooters everywhere, and the old town itself is pedestrian. Park outside the walls and walk. The pay-off comes when you leave: the Jadranska magistrala, the coast road, runs both ways along cliffs and coves, north towards Trogir and Šibenik and south towards Omiš and Makarska, with the islands floating offshore. Ride it early before the summer traffic builds, or in May and October when the light is golden and the heat bearable.
Fuel, mechanics and supplies are everywhere around the city. Food is a joy: grilled fish, black risotto coloured with cuttlefish ink, pašticada stew and the local Plavac Mali wines. Ferries to Brač, Hvar and Vis leave from the harbour, and a bike on an island ferry is a fine way to stretch a ride. In July and August the heat can be brutal in the middle of the day, so carry water and plan the riding around it.