When to book: Five months in advance for up to 15 per cent savings on flights.
ROME
Crumbling ruins, mysterious alleys and the allure of mozzarella, spaghetti and vino makes Rome synonymous with romance. Majestically built across seven hills on the banks of the Tiber River, the entire city centre is a Unesco World Heritage Site. Taking top billing among countless historic sites, are the Pantheon, the Colosseum, the Trevi Fountain, the Roman Forum and St. Peter's Basilica.
Savour sunsets from the Ponte Sant'Angelo, soak up the atmosphere from the Spanish Steps and admire Baroque art at Piazza Navona. To avoid the tourist crush and soaring temperatures, visit Rome in September and October.
When to book: Two months in advance for up to 25 per cent savings on flights.
ISTANBUL
A city that straddles two continents is bound to be a foodie heaven, and Istanbul doesn't disappoint. From juicy kebabs to succulent seafood and moreish meze, your taste buds will thank you for the trip, even if your waistline doesn't. Churches, palaces, dazzling frescoes and enchanting minarets make Istanbul a visual marvel too, with highlights including the Aya Sofya, Topkapi Palace and the Blue Mosque.
For shopaholics, the proverbial Aladdin's Cave awaits at the Grand Bazaar, overflowing with treasures like Turkish rugs, exotic teas and lavish lanterns. For mild weather, I suggest you make a visit in the autumn months from September to November.
When to book: Three months in advance for up to 10 per cent savings on flights.
SEOUL
South Korea's capital city is a thrilling blend of contrasts, resulting in an exotic assault on your senses. Here, ancient palaces rest under high-tech skyscrapers and Western consumerism thrives, while Asian Confucianism lives on. Shop till you drop in designer boutiques or visit Dongdaemun market for local fashion, before soaking up Buddhist history at Bongeunsa Temple.
When hunger strikes, choose fine dining with Michelin-starred chefs, or hit the street food stalls of Myeongdong for grilled cuttlefish and Gimbap. For savings on hotels and pleasant weather, head to Seoul between September and November, or March to May.
When to book: Four months in advance for up to 30 per cent savings on flights.
HO CHI MINH CITY
HCMC welcomes visitors with a colourful vibrancy that's instantly contagious. Whether you want a luxury fix in five-star hotels, a backpacker district jam-packed with bars or an exploration of fascinating history, the former Saigon delivers. Search for souvenirs in Ben Thanh Market, visit the underground tunnels of Cu Chi and take a boat trip on the Saigon River.
Or, zip through neon-lit streets on a scooter, sip cocktails at sophisticated rooftop bars and sample a dizzying array of street food. Don't forget to try snake wine, if only just to say you did it. To avoid the rain of monsoon season, visit between December and May.
When to book: Two months in advance for up to 13 per cent savings on flights.
● Amy Wei is vice-president, Asia-Pacific of travel booking website Kayak.
