Lochaber
The lake
was a loch.
Loch Shiel, beside the viaduct, was Hogwarts Lake in several scenes. In Prisoner of Azkaban, Harry flies across it on Buckbeak.
The Clachaig Inn area was a location for Hagrid’s Hut in Prisoner of Azkaban. The hut was a temporary set; VisitScotland sends fans to the Clachaig Inn, a working inn in the glen.
Sources

Glenfinnan House HotelGlenfinnan House Hotel
Glenfinnan
A 1755 stone house across the bay from the Glenfinnan Monument, a ten-minute walk from the viaduct.
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The Stage HouseThe Stage House B&B
Glenfinnan
The old Prince’s House Hotel, under new owners since 2025, 100 metres past Glenfinnan station. Pictured as it was in 2010.
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