Originally a small coaching inn, the Gorphwysfa Hotel (later the Pen-y-Pass Hotel) was built around 1850 when a narrow road was opened through the Pass of Llanberis. The hotel was entirely rebuilt nearby c.1902, reverting to the original name of `Gorphwysfa?. In an advertisement of 1902, the hotel was described as consisting of a `Spacious Entrance Hall, Bar, Drawing-room, large Coffee-room, Smokeroom, Storeroom, Two Kitchens, Scullery, Front and Back Stairs, Twelve Single and Double Bedrooms, Linen-room, Housemaid's Closet, Bathroom and Lavatory (hot and cold water), W.C., Cellar, extensive range of Outbuildings, and about 48 Acres of land?. The hotel also held the fishing rights to the nearby trout lake Llyn Cwmffynnon. The extensive outbuildings to the rear of the hotel contained the servant quarters, which were complained of as a hut separated from a cow house by a wooden partition in a 1908 court case between the landlord and a former servant. The hotel underwent extensive renovation between 1967 when it was purchased by the Youth Hostel Association and 1971 when it was reopened as a youth hostel.

The hotel/hostel currently consists of a main two-storey elevation with attics to the south-east of which are single-storey elevations with attics built of random rubble and roofed with slate. Across the road to the south are is a further large building, also built of random rubble and roofed with slate, housing the Pen Y Pass Cafe. The main elevation consists of a main wing parallel to and facing the road to the south-west which abuts perpendicularly onto another short wing to the south-east with a long rear wing projecting from just north-west of the centre of the main wing. The entrance is through a depressed arch in a gabled porch coped with red brick and topped with a ball finial at its peak. On either side of the porch are first-storey square windows with two further square windows in the second story above. On either side of this central bay are two projecting bays with coped gables and deep first-storey bay windows. The left bay has two second-story square windows. The right bay is formed by the gable end of the south-east wing and has a single long rectangular window in its second storey. The north-western gable end of the main wing is also coped and has a deep single-storey bay window above which are three vertical second-storey windows.

(Sources: Adams, The Mountain Walker's Guide of Wales (Llanrwst: 1990), p. 42; Welsh Newspapers Online: Gwalia, 06.03.1902; North Wales Observer and Express, 20.11.1908).
A.N. Coward, RCAHMW, 15.05.2018