The Cob is a substantial embankment built across the Glaslyn estuary in 1811 by William Madocks to reclaim land at Traeth Mawr for agriculture.
The opening was marked by a four-day feast and Eisteddfod celebrating the roadway connecting Caernarfonshire to Meirionnydd and which figured in Madocks's plans for a road from London to his proposed port at Porthdinllaen.
Three weeks later, however, the embankment was breached by high tides and Madocks's supporters were forced to drum up money and men from all around Caernarfonshire to repair the breach and strengthen the whole embankment.
By 1814 it was open again, but Madocks's finances were in ruins.
By 1836 the Ffestiniog Railway had opened its line across the embankment and it was to become the main route for Ffestiniog slate to reach the new port at Porthmadog.
In 1927 the Cob was breached again, and took several months to repair.
In 2012, 260 metres of the embankment were widened on the seaward side of the Porthmadog end to allow a second platform to be constructed at the Ffestiniog & Welsh Highland Railway's Harbour Station.

The former tollhouse at the north-western end of the Cob has slate-clad walls.
It is one of the few buildings to retain the interlocking slate ridge-tiles devised by Moses Kellow, manager of Croesor Quarry.
The toll was abolished in 2003 when the Welsh Assembly Government bought the Cob.

Pen Cei, to the west of the harbour was the centre of the harbour's commercial activities.
Boats were built and repaired and there were slate wharves for each quarry company, with tracks connecting to the railway.
Bron Guallt, built in 1895, was the Oakeley Quarry shipping agent's house.
Grisiau Mawr (English: Big Steps) connected the quay to Garth and the houses built to house the ship owners and sea captains, and it was here that the School of Navigation was built.

Melin Yr Wyddfa (English: Snowdon Mill) on Heol Y Wyddfa is a former flour mill built in 1862, where a scheme of renovation and conversion to luxury flats was started, but has yet to reach completion.

The Welsh Highland Heritage Railway, not to be confused with Welsh Highland Railway, is a three-quarter-mile (1.2 km) heritage railway.
It includes an award-winning miniature railway, a heritage centre, a shop and a cafe.

Kerfoots, located in a Victorian building on Stryd Fawr, is a small department store founded in 1874.
It contains a unique spiral staircase, chandeliers and slender cast-iron columns to support the upper floors.
The Millennium Dome, constructed by local craftsmen in 1999 to celebrate the store's 125th anniversary, is made of stained glass that depicts scenes from Porthmadog in 1874.

The Royal Sportsman Hotel (Welsh: Gwesty'r Heliwr) on Stryd Fawr was built in 1862 as a staging post on the turnpike road to Porthdinllaen.
The arrival of the railway five years later brought increasing numbers of tourists, and the hotel soon became famous for its liveried carriage and horses to transport guests to local sightseeing spots.
The building is of Ffestiniog slate; the original stone and slate fireplaces are still in position.

The War Memorial stands on top of Ynys Galch, one of the former islands reclaimed from Traeth Mawr.
In the form of a Celtic cross and standing 16 feet (4.9 m) high, it was fashioned from Trefor granite and unveiled "in memory of ninety-seven fallen war heroes of Madoc Vale" in 1922.

On Moel y Gest, a prominent hill above the town, is an Iron Age stone-walled hill fort.
The Cob is a substantial embankment built across the Glaslyn estuary in 1811 by William Madocks to reclaim land at Traeth Mawr for agriculture. The opening was marked by a four-day feast and Eisteddfod celebrating the roadway connecting Caernarfonshire to Meirionnydd and which figured in Madocks's plans for a road from London to his proposed port at Porthdinllaen. Three weeks later, however, the embankment was breached by high tides and Madocks's supporters were forced to drum up money and men from all around Caernarfonshire to repair the breach and strengthen the whole embankment. By 1814 it was open again, but Madocks's finances were in ruins. By 1836 the Ffestiniog Railway had opened its line across the embankment and it was to become the main route for Ffestiniog slate to reach the new port at Porthmadog. In 1927 the Cob was breached again, and took several months to repair. In 2012, 260 metres of the embankment were widened on the seaward side of the Porthmadog end to allow a second platform to be constructed at the Ffestiniog & Welsh Highland Railway's Harbour Station.
The former tollhouse at the north-western end of the Cob has slate-clad walls. It is one of the few buildings to retain the interlocking slate ridge-tiles devised by Moses Kellow, manager of Croesor Quarry. The toll was abolished in 2003 when the Welsh Assembly Government bought the Cob.
Pen Cei, to the west of the harbour was the centre of the harbour's commercial activities. Boats were built and repaired and there were slate wharves for each quarry company, with tracks connecting to the railway. Bron Guallt, built in 1895, was the Oakeley Quarry shipping agent's house. Grisiau Mawr (English: Big Steps) connected the quay to Garth and the houses built to house the ship owners and sea captains, and it was here that the School of Navigation was built.
Melin Yr Wyddfa (English: Snowdon Mill) on Heol Y Wyddfa is a former flour mill built in 1862, where a scheme of renovation and conversion to luxury flats was started, but has yet to reach completion.
The Welsh Highland Heritage Railway, not to be confused with Welsh Highland Railway, is a three-quarter-mile (1.2 km) heritage railway. It includes an award-winning miniature railway, a heritage centre, a shop and a cafe.
Kerfoots, located in a Victorian building on Stryd Fawr, is a small department store founded in 1874. It contains a unique spiral staircase, chandeliers and slender cast-iron columns to support the upper floors. The Millennium Dome, constructed by local craftsmen in 1999 to celebrate the store's 125th anniversary, is made of stained glass that depicts scenes from Porthmadog in 1874.
The Royal Sportsman Hotel (Welsh: Gwesty'r Heliwr) on Stryd Fawr was built in 1862 as a staging post on the turnpike road to Porthdinllaen. The arrival of the railway five years later brought increasing numbers of tourists, and the hotel soon became famous for its liveried carriage and horses to transport guests to local sightseeing spots. The building is of Ffestiniog slate; the original stone and slate fireplaces are still in position.
The War Memorial stands on top of Ynys Galch, one of the former islands reclaimed from Traeth Mawr. In the form of a Celtic cross and standing 16 feet (4.9 m) high, it was fashioned from Trefor granite and unveiled "in memory of ninety-seven fallen war heroes of Madoc Vale" in 1922.
On Moel y Gest, a prominent hill above the town, is an Iron Age stone-walled hill fort.
Porthmadog