Skansen(the fort) lejonet(lion) is worth a visit.
You'll see the fort from all over the city. The picture is taken from Svingeln in Gothenburg. This building got origins from the middle ages. The first known description of this place is from Birger Jarl who where discussing with the norwegian King Haakon Haakanson about getting rid of the mean danes who where making the area dangerous. Later the king Birger Magnusson built a kind of smaller fort here called Gullbergs house in 1302. In the 13:th hundreds the river Gota elf where wider and the fort closer to the river. During these centuries south of Sweden belonged to Denmark. Sweden just had a narrow area to the north sea through a couple of kilometers in current Gothenburg.
On the west side you'll see two canons that are used for His/her majesty birthday, national day and similar events. Like the kings Name day 28:th of januar, the kings birthday 30:th of april, national day 6:th of june, crown princess birthday 14:th of july, queena names day 8:th of august and queens birthday 23:th of december. Then there is other events for firing the canons. You'll have to keep an eye on the press.
On the north side you've got the entrance. You are able to get some guided tours here. Next guided tour here are the 1:th of September 13:00. You are alos able to join a free guided tour the 6:th og october and 3:th November 2019.
The fort is now used for weddings, dinners and similar events. You are able to hire the entire place for a couple of 100$.
From the top of the building you'll get a good view of Gothenburg and are able to see the other fort, Skansen kronan.