Goslar is a small town in Lower Saxony, at the foot of the Harz Mountains. The main attraction of Goslar is a mine in Rammelsberg. Goslar's mine and old town belong to the UNESCO world heritage sites.
Development of Rammelsberg mines began in 968, although recent archaeological finds suggest that mining was carried out here in the IV-III centuries BC. Initially, the main producing metal was silver, then copper and later lead. The mine was finally closed in 1988.
After the mines were closed, Rammelsberg has become an industrial museum that presents many tools and different techniques of mining production of different eras. You can take a tour; I signed up for an underground tour and for a trip on a small train. The latter is more for children. There is also a 4-hour tour "for diggers" in the abandoned parts of the mine. As a rule, the language of the tours is German, but it's also possible to order tours in English for specific time.
You can walk from the mine to the downtown. I would recommend that you first pass a little backwards. Just in 100 meters there's a beautiful lake and waterfall. Walk around the waterfall at the top and walk along the forest path, so you can see a panorama of all mine buildings. Then go along the road by which you came to the mines. You can go back a little to the bus stop and go by bus.
At the beginning of the old town be sure to visit the Peterstraße Street. German streets are typically straight, but this street with beautiful half-timbered houses is winding.
The city is old and beautiful, come here even without visiting the mine.
On the market square don't miss the performance during the clock chime.
Barock-Café Anders (4, Hoher Weg) has quite inexpensive (~5-6 euros) and great breakfasts, if you're interested.
The most interesting building in the city is the Imperial Palace (Kaiserpfalz), the residence of kings in the Middle Ages. It was built in the 11th century during the time of the Holy Roman Empire.

Monument dedicated to those who returned home from captivity many years after the World War II ©Yuriy Buriak
In the Church of Cosmas and Damian there's an observation deck where you can climb the 239 steps. Each of them has a name of a person who donated to the church reconstruction. At the top, just above the heads, hangs a large bell, beating off automatically every 15 minutes. Be careful =)
During Christmas markets, a beautiful forest of glowing Christmas trees is planted in Goslar.
Getting there: By bus #803 in the direction of Bergbaumuseum from the train station in Goslar.