[5] The present station is sited on the former standard gauge trackbed adjacent to St. Helen's Road, opposite the former locomotive works of De Winton & Co and beneath the high retaining walls of Segontium Terrace, which can be reached from St Helen's Road via a pedestrian footbridge.

The station buildings accommodate the booking office, a tourist shop and passenger facilities.

In the winter of 2005/06, the passenger platform and run around loop at Caernarfon were lengthened to permit the operation of trains up to ten carriages long.

Between Caernarfon and Dinas, the new Welsh Highland line shares the old standard gauge trackbed with the 'Lôn Eifion' tourist cycle track.

[6] A new station to a modern design was built during 2018-19 and was first used for Sion Corn (Santa Claus) trains in December 2018.