Other visitors to the ruins in Arankelle in north central Sri Lanka are looking at the British visitors curiously, wondering why they find so interesting in the murky waters of an ancient pool.
The visitors had come not to view the ruins, but to study and photograph dragonflies that have made it their habitat.
"Just a few minutes ago we found the ghost dragonfly which sit on the wonderful archeology you have," dragonfly watcher Mike Crotton says.
"But my favorite's are the tiny little gems that you get here that you don't get in the UK. Totally beautiful."
With niche markets like dragonfly watching growing in the West, specialized tour operators are now actively marketing dragonflies as a product to position Sri Lanka as one of the top dragonfly destinations in Asia.
The rich biodiversity, easy access to wildlife and a large number of endemic species of dragonflies have made Sri Lanka a good destination for dragonfly watchers.
"Dragonflies might seem a very unlikely mar