The gardens and broader grounds of Tan-yr-allt villa (nprn 16896) were laid out soon after the house was built by William Madocks in about 1800. The house is perched on a steep hillside looking south over Porthmadog and Traeth Mawr, with a view down to Harlech and beyond, and a sheer rock face as high as the house immediately behind it. The house is located in grounds which include parkland (700285), mostly on the north side of the A498 road.

There is little formal structure, the important elements being the view, trees, and the kitchen garden. The garden and woods continued to be maintained and there are flourishing trees of all ages. The original informal layout does not seem to have been much altered. In front of the house, which stands on a narrow shelf in the hillside with its garden below and wooded park above, is a large, sloping lawn from where wide views over Porthmadog and its surroundings and down to Harlech can be obtained. At the foot of the lawn is a small formal pond which once had a cherub fountain; the grassy slope is surrounded by trees. A level lawn to the east also enjoys the view, and from here one can hear the sound of a stream which runs down through the woods nearby. Varieties of rhododendron planted in this area flower successively, giving colour from early spring to midsummer.
Plantations of trees within the garden area extend away to the east and south-west from the house, and contain a mixture of species, both trees and underplanted shrubs. Madocks was a tree enthusiast and was particularly fond of beeches; there are numerous specimens planted by him which have now reached a great size, and these constitute one of the main features of the  property.

Much of the available garden space is occupied by the kitchen garden (700286). 

Source:
Cadw 1998: Register of Parks and Gardens of Special Historic Interest in Wales: Conwy, Gwynedd & the Isle of Anglesey, 296-99 (ref: PGW(Gd)18(GWY).

RCAHMW, 22 June 2022