Just on the southern edge of town lies this 120 metre high hill. Once home to an Iron Age hill fort, the hill is also recognisable for the distinctive monument perched on top.
As far as the history of the site goes, it is known that a fort was built at the summit back around 400BC.
More recently, Pen Dinas saw the addition of the chimney-like monument on top. According to the plaque mounted on it, this well-known local monument 'was built c.1852 in memory of the Duke of Wellington, Victor of Waterloo.' Paid for by public subscription, local belief is that it was once planned to be even grander and topped with a statue of a man on horseback too.
A climb up to the top of the hill on a pleasant day is very rewarding - you can see for miles inland along both the Ystwyth and Rheidol river valleys, as well as out to sea. It's also a brilliant picnic spot, if you avoid windier days.
Pen Dinas, with neighbouring Tanybwlch Beach, has been a local nature reserve since 1999.
Routes to the top of Pen Dinas include: