Architecture in Stockholm
The buildings that survive from this period are mostly churches and royal buildings, since these were built from more durable materials than most other buildings from that period. Birger Jarls torn ("The Tower Of Birger Jarl") was considered the oldest building in the entire city, however, it is now known to have been erected by Gustav Vasa in the 16th century. The Riddarholmen Church from the late 13th century is considered to be the oldest surviving building in Stockholm. While it came to serve as the church of choice for royal burials, another church, the Storkyrkan ("Great Church") came to be used for coronations. Both of the churches have been redesign several times since their erection.
Vätö
Vätö's red granite, which is over 1.7 billion years old, is renowned as a building material. It was extensively quarried from the late 19th century to provide stone for a number of monuments, including the Stockholm Opera House and the Riksdag building. The last of the old quarries was shut down in the 1970s. Limited quarrying resumed in the 1980s in Vätö Stenhuggeri quarry, which was first opened in 1905 and can be visited by tourists. Another quarry, Vätöberg, has been designated as a national monument.