The recreation ground "Medeltidens värld" is closed since about 10 years.

relation/10626308 is wrong

See https://skyddadnatur.naturvardsverket.se/sknat/?nvrid=2000876

relation/5729638 is wrong.

According to both Fagersta Municipality and https://www.gymnasium.se/skola/brinellskolan the school is located at
Fridavägen 5.

According to https://skyddadnatur.naturvardsverket.se/sknat/?nvrid=2028251 the ways 1329306462 and 1329306463 is the same nature reserve (the same entity)

According to https://skyddadnatur.naturvardsverket.se/sknat/?nvrid=2013532 the OSM-ways 881396153 and 881395131 is one nature reserve (one entity).

Update way/43248066 with polygon from

https://skyddadnatur.naturvardsverket.se/sknat/?nvrid=2000299 or https://commons.wikimedia.org/wiki/Data:/Sweden/Nature_reserves/2020/Flarksj%C3%B6berget/2000299.map

The water north of the road is a separate lake, called "Nissagölen"

This is now a outdoor gym (see Google Maps)

The layout and buildings on this square has changed.

Unable to answer "Is this bicycle parking covered (protected from rain)?" – Bicycle Parking – node/1734496232 via StreetComplete 57.3:

Partially covered