It is a rather sweet surprise to most passengers.

Especially for those who have not set foot at Houston’s George Bush Intercontinental Airport (IAH) over the last two years.

A feeling of awe seems to overcome many international travelers as they first arrive at the airport’s now-two-year-old Federal Inspection Services (FIS) facility. It is, after all, the largest structure of its kind in the nation.

Spanning over 784,000 square feet, the FIS has the capability of processing up to 4,500 international passengers per hour. What makes it so impressive; however, is not the speed of service, but the quality of it.

“People just can’t get over how great the FIS is,” says Charles Wall, airport manager for George Bush Intercontinental Airport. “A lot of them will rant and rave about how friendly our staff is and how easy it is to get around the airport. That makes me feel good, because in reality that is what we were going for when we built this facility.”

In 2005, the Houston Airport System inaugurated the FIS as a response to increasing demand from international travelers. A year earlier, more than 6.4 million international travelers had passed through IAH – that number was only expected to increase in the years ahead.

Today, thanks in large part to the international appeal of the FIS, IAH is the fourth-fastest growing airport in the world.

“Travelers take note of anything that makes their journey less stressful,” Wall said. “If they come through IAH and find that their experience here is fast and stress-free they are more likely to come back. They are also more likely to recommend a Houston route to their friends and family.”

So far, that seems to be the case as the number of international passengers at IAH continues to increase. Last year, roughly 7.4 million international travelers passed through the airport.