On the road to Viipuri

Apparently the most accessible bunker of Mannerheim Line is this one - Le-4. It is located directly at the rail-way road Vyborg. It was built in 1920s in the form of a square machine-gun bunker. It's front wall is undermined and interiors almost did not preserved.
PS 2011: There was my starting point for the beginning of mannerheim Line explorations.