Most lakes are quite young in Earth's story — they form when glaciers melt or rivers shift and they usually disappear after a few thousand years. Lake Ohrid is extraordinary because it has lasted for millions of years, long before humans existed. Scientists call very old lakes like this 'ancient lakes', and there are only a handful of them in the world.
The lake is about 30 kilometres long and up to 288 metres deep — that is nearly as deep as the Eiffel Tower is tall! Because the water is so clear, sunlight can reach much deeper than in most lakes, letting unusual plants grow far below the surface. The water stays clean partly because special underground springs feed it directly from the surrounding mountains.
Around the lake there are pretty villages, orchards, and old churches perched on rocky cliffs above the water. The town of Ohrid itself sits on the shore and is one of the most visited places in North Macedonia. Children there often spend summer swimming and fishing, just as children have done here for thousands of years.