One of Britain's most popular and most mysterious attractions, Castlerigg Stone Circle is a must-see sight for visitors to the Lake District. The Neolithic structure, which is comprised of 38 free-standing stones, some of which reach as high as 10 feet (3m), continues to intrigue eminent archaeologists and casual visitors alike - and its original purpose is still not exactly known. Demonstrating a remarkable geometric and astronomical precision (parts of the circle align perfectly with the sun, moon and stars), it is thought that the 5,000-year-old circle once filled a very important ceremonial or religious function. However, part of what makes Castlerigg such a wonderful sight for modern-day visitors to Cumbria, is its breathtakingly beautiful natural setting. Located on a slight plateau, the views afforded from the Castlerigg site are simply phenomenal: 360-degree panoramas of the surrounding fells, and excellent vistas of Cumbria's highest peaks, such as Helvellyn, Skiddaw, Grasmoor and Blencathra. Castlerigg has been called 'the most visually-impressive prehistoric monument in Britain' by archaeologist John Waterhouse, and those who make the short trip from Keswick to view the site certainly will not be disappointed.

Address: About 1.5 miles (2.4km) south of Keswick

Telephone: (0)191 269 1200

Transport: Train to Penrith Station, and then a Cumbria X4/5 bus to Keswick

Opening times: Open daily, all year round

Admission: Free admission