This is the Powderhall branch line of the Edinburgh and Leith Railway, the last part still in existence. It's been unused for almost a decade. (The other lines were dismantled long ago, but many can still be followed as cycle routes like Warriston Path.)
I took the photo from the bridge where the line crosses the Water of Leith, close to Redbraes Park. Gaps in the fence on either side allow you to cross the bridge on foot, and are even marked on OpenStreetMap! @Gaelan and I found the spot while wandering last autumn.
I love how Edinburgh contains so many hidden places, even in otherwise relatively built-up, populous areas. It's a place that rewards exploration.
Standish Hospital, England
Standish Hospital started out as a manor house. Later, it saw a variety of medical uses over the decades. Eventually, it closed in 2004.
Read more: https://www.obsidianurbexphotography.com/medical/standish-hospital-england/