There’s no escaping history when you visit Snowdonia. It’s everywhere you turn. From Iron Age burial chambers and Roman forts to medieval castles and Victorian follies, Snowdonia’s mountains and coast are awash with history.

Some of the oldest historic structures that you can visit in Snowdonia today were built in prehistoric times. There are many prehistoric standing stones in the region, as well as a number of burial chambers and hill forts. Worth a visit are the standing stones in the hills around Harlech, as are the Bachwen burial chamber at Clynnog Fawr and the remains of a prehistoric hill fort at Dinas Dinlle. But arguably the most awesome prehistoric site in Snowdonia is Tre’r Ceiri, a huge Iron Age settlement on the Llyn Peninsula, where a 30-minute upward trek reveals the remains of 150 stone huts and a huge rampart, all on the slopes of Yr Eifl overlooking the Irish Sea 400 feet below.

The Romans left their mark on Snowdonia, too. After overthrowing local inhabitants and occupying their settlements, the Romans built their own formidable fort – Segontium – on the outskirts of modern-day Caernarfon. This fascinating site – one of Britain’s best-known Roman remains – is open to the public along with a museum displaying finds from the fort.

Snowdonia was a hive of activity during the days of the early Celtic Christian church. Many important Celtic religious sites were established in Snowdonia during the 6th and 7th centuries, including monasteries, churches and abbeys. Bangor Cathedral’s origins can be traced back to this era, while the little island of Bardsey off the Llyn Peninsula was home to a Celtic monastery and became an important religious site, where it is said that 20,000 saints are buried. Three pilgrimages to Bardsey equalled one to Rome, and key points along the pilgrims’ route can still be visited today – as can Bardsey itself, which is accessible by boat from Aberdaron at the tip of the Llyn Peninsula.

During the Middle Ages the English king Edward I built a number of castles and walled towns across North Wales to subdue the Welsh, and many of these survive today – mostly in excellent condition. Caernarfon and Conwy castles and their town walls (UNESCO World Heritage sites) are beautifully preserved, while Harlech Castle, perched high on a cliff-edge, has been described as “the definitive Welsh castle”. But it’s not just Edward’s castles that survive; there are Welsh castles too, like Dolwyddelan and Criccieth, which are just as impressive.

But castles aren’t the only medieval buildings still standing in Snowdonia. You’ll see many medieval houses, bridges, churches and other structures in the region, too. Like Ty Hyll, just outside Betws-y-Coed – a cottage which according to legend was built in one night. And the lonely church of St Baglan at Llanfaglan, just outside Caernarfon, with an ancient holy well nearby.

The towns, villages and open countryside of Snowdonia Mountains and Coast are dotted with Tudor and Elizabethan buildings, from modest cottages and farmhouses to elaborate halls and castellated mansions. Two of the best examples can be found in Conwy. Aberconwy House, a merchant’s townhouse now owned and managed by the National Trust, dates predominantly from the 16th century, although parts of the building are a few hundred years older; while at the nearby Elizabethan mansion Plas Mawr – one of Britain’s finest examples of the period – you’ll see some beautiful restored and painted plasterwork.

At Glynllifon Country Park, just outside Caernarfon, there have been several large and important houses over the centuries. The present mansion was built in the early Victorian period, amidst beautiful grounds which include peaceful woodland walks, follies, an old hermitage and a modern slate amphitheatre where you may be lucky enough to catch an open-air concert or play. And there are many other fine examples of 19th century architecture around Snowdonia, like Penrhyn Castle near Bangor and Bryn Bras Castle just outside Caernarfon.

But Snowdonia’s historic sites can also have very modern origins. We tend not to think of 20th century buildings as ‘historic’, and yet Portmeirion Village is just that. Portmeirion – the setting for the 1960s TV series The Prisoner – mixes the old and the new to create one of the region’s most picturesque and popular attractions. Old buildings and ancient woodlands come together with 20th century creations that are traditional in design; new buildings incorporate antique architectural features – like the intricately carved Jacobean ceiling in the village’s Town Hall – and old structures have been lovingly restored. In building Portmeirion, the village’s creator – Sir Clough Williams-Ellis – clearly achieved his aim to “develop even a very beautiful site without defiling it”, and proved his philosophy that “given sufficient loving care one could even improve on what God had provided”.