Chengdu or Shenzhen?

Chengdu has no beach at all. It lies deep in the Sichuan Basin, so swimming means a hotel pool or a water park.

Shenzhen has real sand, though not on its doorstep. Xichong, at the tip of the Dapeng peninsula, is the best of it, Dameisha and Xiaomeisha are busier, and in summer the sea is warm enough for long swims. Allow most of a morning to get out there from Futian or Nanshan.

Chengdu is a food destination in its own right. It is the birthplace of Sichuan cooking, with mapo tofu, dan dan noodles and late-night beef-tallow hotpot served from family counters in residential lanes, and jasmine tea in the park teahouses.

Shenzhen eats well because it draws cooks from all over China, so Cantonese dim sum, Chaoshan beef hotpot and Hakka salt-baked chicken sit side by side, and fish picked from the tanks at Nan'ao or Shekou is a highlight. What it lacks is a cooking of its own and old streets built around eating, so good meals tend to happen in malls and office districts.

Little old fabric survives in either city, but Chengdu has far more to see. There is the Wuhou Shrine, Du Fu's Thatched Cottage, the working Wenshu Monastery and Qingyang Palace, and the Shu gold and jade at Jinsha. Its old lanes are rebuilt, but the sights still fill three or four days.

Most of Shenzhen's landmarks tell the story of its own rise in the late twentieth century: the Ping An tower, Civic Centre and the converted factories of OCT Loft. Nantou old town and the Hakka walled villages add older layers, but they are far apart and quickly seen.

Chengdu goes out for longer and with more spirit, and food is at the heart of it. A slow hotpot dinner leads on to the riverside bar streets around Jiuyanqiao or a cocktail in Yulin, and the snack streets keep serving after midnight.

Shenzhen's nights are split between the bottle-service clubs of Coco Park, Shekou's easy-going pubs and private KTV rooms, with long journeys between them and little happening on the street. It is fine for an evening out but rarely the reason for the trip.

Both give good outdoor days, but of different kinds. From Chengdu the draw is the mountains beyond its flat, hazy plain: Taoist trails on Qingcheng, the long cloud-forest climb of Emeishan with monkeys on the paths, and panda country towards Wolong.

Shenzhen's nature is coastal and closer to hand. There is the headland trail on the Dapeng peninsula, kayaking off the eastern shore, Wutong Mountain's views towards Hong Kong and egrets feeding in the Shenzhen Bay mangroves. The hills are lower, but the sea makes up for it.

Both make excellent bases, Chengdu for ancient heritage and Shenzhen for other cities. Chengdu's days out reach back thousands of years: the Leshan Giant Buddha, the irrigation works at Dujiangyan, the bronze masks of Sanxingdui and wooden market towns such as Huanglongxi.

Shenzhen's strength is its neighbours. Hong Kong is under half an hour away by fast train, and Guangzhou's Chen Clan Ancestral Hall and Macau's Portuguese old town are also close. For Hong Kong or Macau, sort out your passport and visa arrangements before you go, so you can get back into the mainland.

Chengdu has one draw children will remember above all, the pandas at the breeding base, best seen early in the morning, plus a zoo and an aquarium park. Food that is spicy by default and muggy summers need some planning.

Shenzhen offers more rides and variety: the theme parks of Overseas Chinese Town, OCT East, the safari park and a marine park by the beach at Xiaomeisha, with malls that have play areas and a metro with lifts. Both cities feel safe, and in both, little is written in English.

Getting around works much the same way in both. Each has a clean, bilingual metro that reaches the airports and high-speed stations, cheap ride-hailing, shared bikes and a daily life run on mobile payment apps.

The difference is shape. Chengdu is one huge sprawl with a pleasant, walkable heart around Tianfu Square and Chunxi Road. Shenzhen stretches some 80km along the coast, so a beach day from Shekou eats up a morning, and walking only works within districts such as Futian, OCT or Shekou.

Both have polished malls full of international brands, Chengdu around Chunxi Road and Shenzhen in Futian and Nanshan. For things to take home, Chengdu does better, with Shu brocade, Sichuan embroidery, Sichuan pepper and green teas from the mountains.

Shenzhen's appeal is stranger and more modern: the multi-storey electronics markets of Huaqiangbei, the tailors of Luohu Commercial City and painted canvases at Dafen. It suits gadget hunters more than craft collectors.

Chengdu makes your money go further. Comfortable and even upscale hotels cost little, a bowl of noodles from a neighbourhood counter costs almost nothing, and many temples and museums are free or charge modest fees. The main extras are hotpot dinners and train fares for days out.

Shenzhen is one of the pricier cities in mainland China. Everyday meals and the metro are still cheap, but the theme parks, the bars of Shekou and Coco Park and the luxury hotels on Shenzhen Bay add up quickly. A careful traveller can still spend modestly.

Chengdu has more for a night out at a show. Sichuan opera variety shows, with face-changing and fire-spitting, are staged nightly, and its livehouses host indie, folk and the city's own Sichuan-dialect hip-hop.

Shenzhen has good modern halls, including the Shenzhen Concert Hall, home of the city's symphony orchestra. Its programme is mostly touring shows and theatre in Mandarin, though, so it is fine for a concert but not worth planning a trip around.

Shenzhen takes relaxation more seriously, in its own modern way. It has huge bathhouse complexes open through the night, with pools, saunas, sleeping halls and floors of massage rooms, foot-reflexology parlours on every block and hot springs in the hills around the city.

Chengdu's calm is gentler and more social. You find it in the bamboo chairs of the People's Park teahouses, among the mahjong players and the ear-cleaners, and in the cheap massage parlours on most streets. There is no bathing tradition in the city, and the rest comes in afternoons rather than whole days.