Imagine flying from New York to Bangkok, spending three days in Tokyo on the way, and paying the same number of miles as a simple one-way ticket. That is what a free stopover offers, and it is one of the best-kept secrets in award travel. Several airline programs still allow it, and using one well can turn a single trip into two holidays for the price of one.

A stopover is a break in your journey of more than 24 hours in an intermediate city, as opposed to a layover, which is shorter. Most airlines charge extra for stopovers or do not allow them on award tickets at all. But a handful of programs treat them as a feature: Air Canada Aeroplan, Alaska Atmos Rewards, ANA Mileage Club, Turkish Miles and Smiles, Icelandair, and Emirates are among the best known for generous stopover rules.

The details vary by program. Aeroplan allows one stopover per one-way award for a small additional fee in points. ANA allows stopovers on round-trip awards. Icelandair famously lets you stop in Reykjavik for up to seven days at no extra cost. Before planning, check the current rules for the program you intend to use, because stopover policies change and older guides often describe rules that no longer exist.

Start by choosing your stopover city deliberately. The best choices are cities you genuinely want to visit that sit naturally on your route, such as Tokyo on the way to Southeast Asia, Istanbul on the way to Europe, or Reykjavik on the way across the Atlantic. A stopover in a city you do not care about wastes days you could spend at your destination.

When searching, use the airline's multi-city or advanced search tool rather than a simple round-trip search, and build the itinerary as two segments with the stopover city in the middle. Some programs require calling to book a stopover, which takes longer but is often worth it. Allow at least two or three days in the stopover city, because one day is barely enough to see anything, and check whether you need a visa for the stopover country.

A stopover works best when you treat the intermediate city as a real destination rather than a waiting room. Book a hotel in a central area, plan one or two highlights, and leave room to wander. Because you are only there for a few days, focus on the experiences the city is famous for rather than trying to see everything.

Stopovers also help with jet lag: breaking a very long journey into two shorter flights with a few days in between is far more comfortable than flying fifteen hours in one stretch. Some travellers deliberately choose stopovers to make long-haul travel with children easier. Think of the stopover as a feature you are using on purpose, not a complication, and your trip becomes richer for it.

Another clever use of stopovers is to visit a city that would otherwise be too expensive to reach on its own. A stopover in a place like Singapore or Dubai on the way to somewhere else lets you experience a city that might not justify a whole trip by itself, but is perfect for three days. Some travellers plan their entire route around the stopover, choosing a destination based on which interesting city lies on the way rather than the other way around. If you are flexible about your final destination, this approach can produce wonderfully unexpected trips. Just remember to check the visa requirements for the stopover country well in advance, since some nationalities need a visa even for a short stay, and that paperwork takes time.

A free stopover turns one award ticket into two trips. Choose a program that allows them, pick a stopover city you actually want to see, build the itinerary with the multi-city tool, and enjoy a second destination for almost no extra miles.