Cadw’s Open Doors Festival is back, providing access to Wales’ most extraordinary and treasured historical locations.

Throughout September, more than 200 historic landmarks across Wales will host a range of free events, guided tours, and immersive experiences, some for the very first time. This year’s Open Doors event is especially poignant as Cadw celebrates its 40th anniversary with an exciting year of activities.

From castles and churches to clock towers to ancient burial chambers, and even Dylan Thomas’ Boat house, there are a huge range of locations taking part. Twenty two iconic Cadw monuments, including Harlech Castle and Strata Florida Abbey will welcome visitors free of charge, inviting them to explore these remarkable places.

Ffion Reynolds, Cadw’s Heritage and Events Manager, said: “Open Doors is a chance for us to celebrate the diversity and resilience of Wales’ historic architecture in a way that’s accessible to all.

“By offering free access to these locations, we hope everyone will have the opportunity to experience the depth of our country’s history and culture and play a role in preserving these places for future generations.

“This year also marks a significant milestone for Cadw - its 40th anniversary; it’s great to host the festival as part of the wider celebrations throughout the year.”

A full list of locations participating in the festival can be viewed on Cadw’s website, but some of those in north and mid Wales include Segontium Roman Fort, Caernarfon (8 September, 10am-2pm) and the Roderic Bowen Library and Archives, UWTSD (28 September, 12pm-4pm), a nationally important collection of 35,000 historic volumes, including eight medieval manuscripts, and 69 books printed before 1500. Also, Harlech Castle (Sat 28 September-Sunday 29 September, 11am-4pm). Guide Siân Roberts shares the stories behind the stones of this spectacular structure in its stunning Eryri setting.

Travel in time from the days before the building to the 21st century, and find out who and what have made this castle so famous and so worthy of being part of a World Heritage site.

The tours will be at 11am, 1pm and 3pm.