Richborough Castle, the modern name for what is left of the Roman fort Rutupiae, rears its great bulk against the skyline about one mile to the northwest of the town. This guarded the southern side of the Wantsum channel when the sea flowed around the cliff on which the Castle stands.
It was here that Claudius' invading army landed in A.D. 43 and the ditches dug by his legionaries can still be seen.
Traces of first century wooden buildings and other remains show that Richborough was the main port of entry and supply depot during the first two centuries.
Inside the fort is a large cross of masonry resting on a deep foundation which formerly supported a large monument faced with marble and adorned with bronze statues erected A.D. 80-90, probably commemorating the conquest of Britain.
From the second half of the third century it formed, together with the Forts at Reculver, Dover, Lympne and Pevensey, a line of forts under the authority of the Count of the Saxon shore.
There was a town at the foot of the fortress called Stonar, which, unfortunately, was destroyed by a great flood in the year 1365 A.D.
Extensive excavation has brought to light foundations of many Roman buildings and numerous objects of antiquity and interest which can be seen in the museum on the site under the control of the British Heritage.