_Trewan_, the seat of Richard Vyvyan, Esq, the late Sheriff for the county, is situated on the brow of a hill facing the south, commanding a fine view of the town of St. Columb. It is an irregular building of granite, said to have been erected in the year 1633, and the interior contains several handsome apartments; but the drawing room being richly ornamented with sculpture, representing the principal events of the Book of Genesis, is highly deserving of notice.—There are also a few good portraits, and a fine picture of a Shipwreck, by Vandervelde. ST. COLUMB MAJOR, as it is called, to distinguish it from a parish of the same name adjoining the village, but of less consequence, is a considerable market town; and although not situated on the high mail road to Truro, yet is a town of some importance on the northern side of the county. It is built on an eminence, and contains a few good houses; the _Market-house_ has an antient appearance. It is situated 11 miles north-west of Bodmin, and 15 from Truro; but after leaving the regular high mail road, the other roads winding to the town are very bad and dirty. The _Church_ is a large antient fabric; but has, perhaps, been injudiciously altered from its original design. The interior contains a variety of memorials, one of which has a handsome bust of the deceased Robert Hoblyn, Esq. of Nanswhyden, who represented the City of Bristol in three Parliaments, and died in the year 1756. The living of St. Columb is the best in the county, and computed to be worth at least £2000 per annum, and in the gift of the Rev. George Moore, of Garlennick, near Grampound. The population of the parish, according to the late returns, amounted to about 2,493. It has a market every Thursday, and two fairs annually. About two miles from the town, to the left of the road leading to Bodmin, but in St. Columb parish, is _Castle-an-Dinas_, a noble entrenchment, originally fortified with three circular walls, and an immense ditch. It is generally supposed to have been constructed by the Danes, and was a permanent fortified residence of some Scandinavian Chief. The diameter of the space enclosed, is 400 feet; and the principal ditch is 60 feet wide. Castle-an-Dinas, Dr. Borlase says, consisted of two stone walls, built one within the another, in a circular form: the ruins he describes as fallen on each side the wall, shewing the work to have been of great height and thickness: he also mentions a third wall, built more than half way round, but left unfinished. This remain is seated on the highest hill in the hundred of Penwith. From St. Columb to Padstow, the distance is eight miles, but the country between those places does not present any thing deserving particular observation.