Previously, one of the many bends of the River Gauja passed directly along the Spoguļu Cliffs, leaving visible traces in the rock face. Over the course of time, as the Gauja carved its way deeper into the valley, the waters of the river, seeking a more direct route to the sea, cut through the bend in the river at the narrowest point and continued flowing along the new bed. Both ends of the loop gradually silted up, forming a closed water-body. This is how all the oxbow lakes along the bank of Gauja were formed.
The water supply in this former river channel is greatly supplemented and clarified by the springs flowing from the Spoguļu (Mirror) Cliffs, making the water clean and clear. The cliffs are reflected in the clear water as in a mirror, giving rise to the name.
The 140 m long and up to 10 m high sandstone cliffs are remark- able natural sites in the River Gauja Valley. The cliffs face is stud- ded with small caves, crevices and hollows. Several major springs emerge at the base of the cliffs, where there is a former channel of the River Gauja. In the rock face, a few meters above ground level is the 3,8m long Trijstūra (Triangle) Cave - a niche adorning the cliff like a temptation out of reach. The Spoguļu Cliffs were exposed comparatively recently - only 4-8 thousand years ago, when the water of the River Gauja carved their way down until they finally exposed the sandstones wall, thus reveal- ing evidence of much earlier date - Devonian rock strata. The sandstone rock is about 350 million years old and developed as sand gradually accumulated on the seabed, at a time when the whole territory of Latvia was covered by the Devonian Sea. Look- ing carefully at the rock, the observant visitor will notice several bedding planes.
For many years, the Cīrulīši Cliffs were frequented by the visitors, who unfortunately scraped their makes on the rock, as every- where else.