One doesn't expect to find waterfalls in the middle of the hilly Danube valley, and yet there they are – hidden amid karst crevices and familiar only to a handful of people, they turn up as a surprise.

The waterfall in the village of Hotnitsa is one of these serendipitous sights. In fact, it is one of the two reasons for the relative fame of this village in the Veliko Tarnovo region. The other is the colony of expats, mostly from the UK. According to most recent data, they own about a hundred of the 500 houses in the village.

Kaya Bunar, or the Hotnitsa Waterfall, forms where the Bohot River leaves the embrace of a karst canyon and falls from 30 m height, forming a small pond with stunningly blue water. The place has been a popular day-trip destination since the Socialist era. Back in those days there was a pub near the waterfall. The food there used to be so good that many people went there to have a meal rather than to enjoy the view presented by the waterfall.

Today the pub is a ruin overgrown with weeds, but two other establishments offer grilled meat and beer in the warm months. Besides the smells and music booming from them, few things will distract you while you're enjoying the sound of the falling water, the sunlight in the sprinkles of water and the pond's surface.

An eco path near the waterfall is an opportunity to explore the environs and to discover the other small wonders created by the Bohot: rock crevices and ponds, along with a vista of the river's canyon at the end. It is about 1.5 km long and not in top condition, but it is manageable.

However, Hotnitsa hides also other secrets.

In 1907 the rocks around the waterfall were the stage of a bold experiment. It was from here that one of Bulgaria's first flying machines took off. Resembling a paraglider, it had been constructed by two Hotnitsa engineers – one of them was the architect who designed the Opera House in Sofia.

The experiment – it was a success – wasn't the first historical event to take place in Hotnitsa. Some 7,000 years ago, when people already knew how to melt copper into implements and weapons, there was a settlement here quite large for the then standards. But the people living in it possessed also other valuables, and during excavations archaeologists dug out nearly half a kilo of gold jewellery.

The gold rings and plates from Hotnitsa resemble very much the ones from the famous Varna Treasure, which is believed to be the oldest wrought gold in the world.

The conclusion is astonishing. Today Hotnitsa may be a small, quiet village with potential for green tourism, but seven thousand years ago it was a busy centre of one of Europe's first civilisations.