What's the must-see thing in Antalya?

Walk through Hadrian's Gate on Atatürk Caddesi and you'll understand why this is the starting point, not a checkbox. The arch dates to around 130 AD, built for Emperor Hadrian's visit to Pamphylia, and it still functions as the actual entrance to Kaleiçi, the old walled quarter. Three marble arches, each about 8 metres tall, framed by Corinthian columns that have gone the warm amber of spilled tea in the afternoon light. No ticket. No hours. You walk through it the way people have for roughly 19 centuries, with the smell of roasting chestnuts drifting from the cart that's usually parked a few metres south. Inside Kaleiçi, the streets tilt downhill toward the old Roman harbor, tight enough that you can touch buildings on both sides. The stone underfoot is polished slippery by centuries of foot traffic, so watch your step in sandals. Mind you, the harbor itself is mostly tour-boat berths now and overpriced fish restaurants. Skip the harbor-front tables and walk up to Hesapçı Sokak instead, where a Turkish coffee runs about 100 TRY, roughly $2.

The Antalya Museum sits on Konyaaltı Caddesi, about 3 km west of Kaleiçi, and has been open since 1922. The collection tends to surprise people who expected a small provincial gallery. The Hall of the Gods holds over a dozen full-size Roman marble statues excavated from Perge, a city founded around 999 BC about 18 km northeast of Antalya. The figures still carry their original surface polish in places, smooth and luminous even behind glass. That room alone is likely worth the admission. The whole museum takes 2 to 3 hours if you read the panels. Worth noting, the air conditioning inside makes it the best midday refuge when temperatures climb past 35°C in the early afternoon during June. Take the Antray tram from Kaleiçi to the Müze stop, about 12 minutes.

The Lower Düden Waterfalls drop about 40 metres directly into the Mediterranean from the cliffs east of Lara Beach. You hear the falls before you see them. The viewing platform shakes slightly from the force of the water, and the mist soaks your clothes if the wind shifts. To be fair, the Upper Düden falls in Kepez, about 12 km north, have a calmer park setting where you can walk behind the curtain of water. But the Lower falls are the one that photographs don't prepare you for. The scale only registers when a tour boat passes underneath and looks the size of a bathtub toy. No reservation needed. Entry to the Lower Düden park is free. A taxi from Kaleiçi runs about 150 TRY, roughly $3. The cliff faces west, so the spray catches direct sunlight after about 5 PM in summer.

What about Perge and Termessos? Both are legitimate day trips, but neither belongs on a first-timer's list for the first 3 days. Perge sits 18 km east on the D400, and it's a flat exposed site with limited shade that reaches 40°C in summer. Budget 3 hours minimum plus transport. Termessos is wilder, a mountain site at about 1,665 metres elevation with no restoration and uneven trails. It requires hiking shoes and a half day. If you have 3 days, spend the first walking Hadrian's Gate into Kaleiçi, the second at the Antalya Museum and Konyaaltı Beach, and the third at the Lower Düden Waterfalls with an afternoon swim at Mermerli Beach, the tiny paid beach below Kaleiçi's walls where the water is startlingly clear and cold even in June. That sequence moves east to west across the city and avoids backtracking.