After a coffee in the white-marble-paved Narochi Trg (People's Square), I head for the Golden Gate, once the most important entrance to the city. On my way I pass the impressive Gothic Papalic Palace and visit one of the world's smallest churches, the sixth-century St Martin's, built in a guard passage above the gate.  Just over 1,700 years ago it was through the Golden Gate that Diocletian allegedly entered his home for the first time. Today it is Ivan Mestrovic's imposing statue of 10th-century Croatian bishop Grgur Ninski outside that catches the eye.  In the evening, I catch a ballet company rehearsing for the summer festival in the handsome Trg Republike square and listen to locals singing age-old Adriatic melodies (klapa) on the Riva.  I finish the night by joining locals for a shot of rakija (grappa) at the friendly Rakijarnica bar in the lively former ghetto area on the west wall of the palace.  I head back to the hotel through the Golden Gate and rub the shiny big toe of Grgur, which apparently guarantees you will return to Split. I certainly hope it works, as this city has been a revelation – if it's good enough for Diocletian, it's good enough for me.  Croatia Airlines (00385 1667 6555; www.croatiaairlines.com), easyJet (0905 821 0905; www.easyjet.com) and Wizz Air (0906 956 0002; www.wizzair.com) fly to Split. The Pleso prijevoz shuttle bus meets every scheduled flight (£5 to the palace). Alternatively, a taxi to the city centre will cost around £40.  Adriatic specialists Completely Croatia (0800 970 9149; www.completelycroatia.co.uk) offer packages to Split; three nights at the Peristil Hotel, for example, costs from £429 per person in low season, including flights from London and private transfers.  A stone’s throw from the Peristyle, this hotel has 12 tastefully decorated rooms, some featuring the original wall of the palace (00385 21 329070; www.hotelperistil.com; doubles from £105).  This small hotel is situated up the steps from the Peristyle where Diocletian had his private living quarters. Only a few rooms, so book in plenty of time (239329; www.vestibulpalace.com; from £155).  Fantastic new hotel with very comfortable, funky rooms a short walk from the palace (314445; www.hotelluxesplit.com; from £170).  One of the best pizzerias in the old town, with a large outdoor terrace (Toncieva 12; 347932).  Tucked away in the quiet Veli Varos area, this small place specialises in fish and seafood (Sperun 3; 346999).  Superb, simple and cosy place near the Iron Gate. Serves mainly fish and excellent pastas and risottos (Bajamonte Ul).
Nick Harrison offers an essential cultural guide to Split, a Croatian city   with a seafront promenade that seduced a Roman emperor.