This stereo photograph shows Caernarfon Castle in Gwynedd. Notice the sailing ships alongside the quay nearest to the Castle. These ships would be loading slate from the quarries Blaenau Ffestiniog ready to be exported across the globe. In the foreground appears to be a raft of timber being floated on the River Seiont.
The Castle was built by Edward I 13th-14th century AD and is now a World Heritage site.
The stereo photo is by Realistic Travels and printed on the bottom right says "Scene of the Investiture of the Prince of Wales". (This was the Investiture of Edward VIII in 1911) Printed on the right hand side it says "By Royal Command of King George V and Queen Mary" The date of the photo is probably around 1911 or a little later.