Of the three Landmarks in the Rhiwddolion valley, Ty Uchaf (’Upper House’) is the oldest; on the evidence of a datestone surviving in the ruined pigsty, it was built in 1685. It is typical of its time: single-storeyed, with an end chimney, and two main rooms with extra sleeping space provided in a loft which originally extended over two-thirds of the cottage (the croglofft), accessed by a ladder. The room to the right of the door, with the big fireplace, would have been the principal living and cooking room, and the smaller, unheated one on the left either a service bay or a primitive parlour; the two rooms were originally separated by a partition. The byre beside the house was probably added in the late 18th century, and may have replaced an earlier structure – the farm would always have required at least one building to act as cow byre, stable and hayloft. The house roof would have been thatched, but it is possible that the byre was slated from the first, and that the house section was re-roofed in slate at the time that the byre was added on.
The roofless structures at either end of the house-and-byre range are 19th-century additions: the one on the left seems to have served as a store, and that on the right may have been a dairy or brewhouse. The dry-stone walls in front of the house, and the now-ruined pigsty, are of about the same date. Various pens, enclosures and other structures, some now only identifiable as footings, can be seen near the house; of these, the only other roofed structure is the ty bach (little house), which is probably late Victorian.
The name Ty Coch means "red house", though there is no obvious reason for this; it may in a general way mean "warm", from the hospitality offered there, or it may be derived from the less cold colour of the stone compared with dressed slate slabs, or perhaps it had a red front door. It is probably a hundred years or so younger than Ty Uchaf, being built before the end of the 18th century. It seems however that it may incorporate the materials of an earlier structure, since it contains a cruck, formed from the trunk and branch of a single tree, spanning the fireplace. The structure may have been a barn, since cruck trusses continued to be used in agricultural buildings well after their use in domestic buildings had been abandoned. In its original layout Ty Coch was not very dissimilar to Ty Uchaf and once had a similar sleeping loft.
For centuries the pattern of farming life continued almost unchanged but the revival in the area of lead mining and then of slate quarrying on an industrial scale transformed the valley. A row of miners’ cottages was built on Sarn Helen (the old Roman Road) and in 1860 a school and a chapel were provided. In 1869 the Bard Griffith Hugh Jones became headmaster and for the next 50 years the district was enlivened by his brass band, his choral union and his eisteddfodau. The chapel choirs sang hymns of his composition and the Rhiwddolion chapel sensationally acquired a harmonium to accompany them. In 1892 Ty Capel was enlarged and an open-air auditorium built alongside for special occasions.