
Dolbadarn was one of three castles built by Llewelyn around the same time to defend the major routes through Snowdonia (the others being Dolwyddelan and Castell-y-Bere). The castle ruins consist of perhaps the finest surviving Welsh round tower and adjoining stone walls. The main structures were reached by way of a portcullis.
One of the interesting features of the tower is that the spiral stair inside the thickness of the wall reverses direction halfway up, a deliberate feature to make it difficult for sword-wielding attackers to reach the upper floors.

It is possible that Dolbadarn was used to imprison Owain ap Gruffudd between 1255 and 1277. After the defeat of Llewelyn ap Gruffudd in 1282, Dolbadarn was captured by Edward I.
Edward had no need for Dolbadarn, preferring instead to build a new and much stronger castle at Caernarfon, and Dolbadarn was dismantled and left to decay. We know little more of its later history, save that Owain Glyndwr may have briefly used it to imprison his enemies during his early 15th century uprising.
The castle is reached by way of a short footpath that can be muddy in wet weather, so do wear good waterproof footwear!