The Groudle Glen Railway dates back to the 1890's when the true narrow gauge railway was built to cater for a holiday population whose ideals were short walks and the taking of bracing sea airs.

In the late 1890's local entrepreneur Richard Maltby Broadbent obtained a lease on the land surrounding the Groudle river from the Howstrake Estate. The area was developed as an attraction for visitors. In 1893 the Groudle Hotel was completed and the Manx Electric Railway officially opened as far as Groudle in September of the same year. The Glen was developed with rustic bridges over tumbling streams. A rocky inlet in the cliffs was dammed and closed off with sea lions and polar bears being introduced. The construction of a two foot gauge railway from the upper part of the Glen at Lhen Coan to the new zoo atttractions began. The line was built using entirely local labour during the winter of 1895-1896. A steam locomotive 'Sea Lion' and three passenger coaches arrived for the opening of the new railway on the 23rd of May 1896. The new railway was an immediate success, so much so that extra coaches and a second steam locomotive 'Polar Bear' were acquired in 1905.

Following the first world war the two steam locomotives were replaced for a short period by battery electric locomotives. The battery locomotives proved unsuccessful and the steam locomotives were overhauled and returned to service. Following the second world war the railway re-opened with only 'Polar Bear' operating as far as the headland. The line to the terminus at Sea Lion Rocks was unsafe and the zoo had closed. The railway continued operating summer seasons up until 1962.

The following years saw the removal of the two steam locomotives and the remains of the coaches. The buildings were demolished and the rails removed. The line became overgrown and forgotten only to be disturbed by the occasional walker.