Caernarfon is known for its medieval castle, but its history stretches another millennium back. The Romans set up camp here under this name, and from this elevation they had views of Snowdonia to one side and the waters to the other. You now have these same views plus the fortifications of the buildings that once stood here.
The grounds are fenced, so you are advised to adhere to the visiting hours. The museum may or may not be open when you arrive - it wasn't during my visit. As such, I can't totally vouch for what this site offers completely. Know that in my case my enjoyment of the site was based on my attempts to imagine the times of the past more than what is actually seen here. There are more evocative Roman sites in Britain, and while the scenery is nice it can admittedly be observed throughout Caernarfon (certainly from a tower of the castle). But I am an American, and cannot easily call a site with visible Roman heritage "average". I'm giving it a 4-star rating in this case, assuming that the museum provides good info.
I would not call this an essential site to see in Caernarfon, but it's certainly worth the half-hour trek there and back to see it if you have the time. Standing on the site, framing the structural roots of the building in the forefront, the castle in the distance, and the estuary beyond, you feel like you are gazing through multiple eras of history simultaneously. read more