One of the most distinctive sites of Vietnam, if not the entirety of Asia, Ha Long Bay is an incredibly distinctive archipelago that tourists are unlikely to find anywhere else in the world.

The UNESCO World Heritage Site, found near the city of Haiphong, features nearly 2,000 different tree-covered limestone islets.

However, in addition to the tiny islands that have come to define it, the area is home to a great many caves and grottos, with some waiting to be discovered.

Whilst it all sounds like something out of an Indiana Jones film, fortunately, there are a wide range of companies that offer tours directly from the bay.

As a result, during my time in Vietnam, I took the opportunity to sail amongst the islets and explore some of the better-known ones.

As with all trips, getting to the caves of Ha Long Bay is all part of the adventure. Many of the tours around the bay use rather old-fashioned wooden boats where passengers can choose between sitting inside or standing on the open deck above to take in the views.

I also saw plenty of authentic fishing boats, covered in lights to attract sea creatures, which are commonly the livelihood of residents living in one of the many floating villages in the area.

Whilst I sadly didn’t see too many fish on the journey to the caves, looking toward the islets did help me to see a few macaques from a safe enough distance that I did not have to worry about them stealing my hat.

After around 45 minutes, the boat arrived at the Sung Sot Cave, one of the most highly regarded in the area. The name can be roughly translated to ‘Surprise Grotto’, a name that managed to live up to the hype.

The name, which was first used in 1901, describes the fact that the cave effectively has a pair of rooms that are connected by a small passageway, not to mention plenty of stalactites and stalagmites.

Leaving the boat and climbing the 100 steps to the entrance of the cave, I was initially a little bit apprehensive by the large crowds on the way in.

However, I need not have worried. According to the travel blog Halong Hub, the cave is large enough to house more than 1,000 people and is nicely lit to prevent anyone from stumbling over uneven surfaces.

Perhaps one of the most interesting elements of visiting the cave is trying to spot all of the unique formations that can be found inside. A few moments with an open mind and I was able to see a range of animals and patterns in the rocky surfaces.

Nevertheless, those who really want to appreciate the finer details in the formations should try to stick by the tour guides, who were all very clued up about the area.

For tourists who like to impress their loved ones with tales of adventure once they get back from their holiday, a trip to Ha Long Bay very rarely fails.

There will not be too many people willing to hire a boat on a quest for untapped caves but a tour to one of the known grottos is just as impressive.

In most cases, full-day tours cost around £30, though visitors should check exactly which caves they visit and if it includes any snacks or lunches.