I visited several towns around Dresden recently, and Altenberg was one of them. It is in a mountainous area close to the border with Czechia and is known for cross country skiing among Germans.
Altenberg is also one of the mining towns collectively nominated by Germany for a WHS. It sounds like it is for sure to become a WHS within a few years.
I visited on a morning trip on a Sunday by train from Dresden.
Both the tourist office and the mining museum were open on the Sunday morning.
So I visited the museum by one of the entrances to the tin mine and then went to see what they call "Pinge," a huge hole that was created when the mine collapsed in 1620. The diameter today is about 400 meters, and the depth is about 150 meters.
PHOTO 1: The banner reads, "Wir sind auf dem Weg zum Unesco-Welterbe," which means, "We are on the way to Unesco World Heritage."
PHOTO 2: One of the entrances to the mine.
PHOTO 3: There is a 1200 meter-long fence surrounding "Pinge." The sign reads, "Bereten verboten: Lebensgefahr!" I later found out that it meant, "Entrance forbidden: Fatal!"