My family, including my two 10-year old twin daughters visited the castle in July 2018.
The generally-used car park is at the foot of the tor on which the castle sits, and to access the castle this way, you have to pass through a farm and pay a fee. My understanding is that this fee is to cross the farm. It isn't a fee for parking or a charge to access the castle as such. The reason I say this, is that you can walk from Dolwydellan (or park further back down the road) and by-pass the main park and farm entirely. This route isn't secret, isn't barred and is open to the public; it's just not advertised as an access path. We were told about it by a lady in the village.
So, onwards to the castle and it's a fairly steep climb, although the distance isn't that great - maybe quarter of a mile from bottom car park to castle. It is steep though and it isn't wheel-chair/buggy friendly.
The castle itself, one of the remnants of one of the many Princes of Wales of old, is a ruin, but has an enclosed keep which you can access by the stairs aside the old wall. If the door hadn't been open, it wouldn't have been obvious you could go in, but it's worth doing as the hall is full of information about the building's heritage.
If you're in the room, head off to the far right corner and some beautiful stone steps working their way up to the ramparts above. My children loved it - the ramp upstairs gives you access to unparalleled views across the river and valley below. Turn around to see the stunning Welsh Snowdonian vista. We spent ages up there despite the drizzle!
In summary, if you're looking for an interesting diversion for an hour or two (it's not somewhere you'd spend the whole day, probably) then this is a great place to visit. You don't have to pay if you're prepared to walk from bit further afield.
Own or manage this property? Claim your listing for free to respond to reviews, update your profile and much more.