On one of my first walks in Lumphini Park, I was mainly looking for some relief. I wanted to escape the capital’s sweltering afternoon heat in the shade of the old trees—and was startled.

Suddenly, a reptile almost 2 m long lay on the lakeshore, resembling a fearsome dragon.

It then moved slowly and calmly along a path through the park.

And right in the middle of a city of millions.

In fact, monitor lizards have always been part of Thailand's natural wildlife. In Bangkok, they are almost always Asian water monitors, commonly known as “monitor lizards.” They are the world's second-largest lizards, after the famous Komodo dragons.

They prefer to live near water—in rivers, canals, lakes and wetlands. That’s why they also thrive in the city’s large parks.

Lumphini Park is particularly famous for them. They’ve become an almost everyday sight there. Nearly 400 are said to roam the park each day. Within minutes, many visitors spot them by the water, basking in the sun, swimming, or slowly making their way through the grass.

Water monitors also live in neighboring Benjakitty Park.

However, visitors are often more drawn to the expansive wetlands, birdlife and modern skyline.

The monitor lizards are less conspicuous here and are more a part of the overall nature experience. But if you keep an eye out as you stroll along the quieter banks, you can spot them there, too.

There are several reasons why the animals have spread so widely in Bangkok. The city provides them with plenty of water through its many canals, enough food, and few natural predators.

Monitor lizards eat fish, frogs, small animals and carrion, among other things. This means they also play an important role in the urban ecosystem, helping to clear away organic waste.

They are usually harmless to people. They don’t attack without reason and will generally try to avoid you. They only become a problem if they are harassed, touched or fed.

That’s why you should always keep your distance and leave them alone. Simply watching them can be an impressive and peaceful encounter with one of Bangkok’s most unusual residents.

The monitor lizard’s Thai name, “Hia,” is also interesting. However, use this word with caution, as it is also considered a strong swear word in everyday speech—reflecting how little regard Thai people have for this remarkable animal.

But for most visitors, monitor lizards are now an integral part of the Bangkok experience and a popular photo opportunity.