Glen Ogle

The old railway viaduct at Glen Ogle is one of those Scottish Lowland spots that catches you off guard. You're driving through proper countryside near Lochearnhead when suddenly there it is - a Victorian iron structure arching across a deep wooded gorge like something from a Brunel fever dream. Built in 1899, it's been closed to trains since 1965, but the engineering is still magnificent.

What makes it worth stopping for is the walk underneath. Park near Lochearnhead and you can hike down into the glen itself - the path runs along the old railway line with the viaduct looming above you, all red sandstone and cast iron. It's maybe forty minutes from the car park, steady rather than steep. On a clear day the light through the arch is genuinely striking, and photographers will find themselves spending longer here than expected.

It's not a theme park experience - there's no visitor centre, no cafe, no interpretation boards. You're essentially looking at an abandoned Victorian railway bridge in a glen. That's either exactly what you want or you'll find it a bit underwhelming, depending on your mood. Families with younger kids might manage half an hour before restlessness sets in; walkers and history types will spend two hours easily.

If you're based at Balquhidder Braes Holiday Park nearby, it's a cracking afternoon detour. The walk beats a museum visit on a decent day, and it's free. Go when it's not raining - the glen can get gloomy and muddy when wet.