Is there anyone who have some info on undergroud bases in the northern part of europe like Sweden, Norway, Denmark a.s.o. Are there any underground bases in the northern part of europe and what does the government know about it?

Well, im not sure i would call it an underground base since it was never finished as far as i know. But we have something like it near where i live in Norway.
During WWII the Germans started building a underground submarine base in a mountain along the coast. I remember we did a school project about it many years ago, though we only went as far as the entrance. I don't remember many details, it's been a long time. The entrance we went to was a cave in the mountainside, im not sure if they got as far as to make an entrance for the submarines.

Just thought id tell ya about it

Well, I did mention the ones in outback Australia.

Honestly why would aliens want underground bases on earth?

If you're talking about underground military bases then presumably any operational ones will still be top secret, but the respective goverments will know all about them since they would have built them?

I would have thought some would have been built during the cold war. At the very least, goverment and miltary command centres - as we have/had here in the UK.

Can't help with any details though.....

(Oh, and if you're talking alien bases, forget it )

There is a long history of cave-like military bases in the Nordic countries. Norway and Sweden has built navy bases into waterline caves to hide their coastal submarines and fast missile boats. I believe both have underground airbases like Switzerland (though things like that are kept quiet) to prevent looses from an enemy first strike.
In northern Norway, during the Cold War, there was an underground supply base to maintain an US Marine Corp artic brigade for up to 90 days, The US Marine Corp being the dedicated US force to assist the Norwegian Army in case of an Russian attack in the north.
Every country that can afford it will put their prime assets underground. They are harder to find, hard to attack and easier to defend.

Here's a conspiracy in itself.

4 people thought Nordic = countries.

I thought it meant the tall blonde aliens.

Could the question asked at the beginning have been a test to see our knowledge on the governments and aliens.

I don't know about all that, But it would stand to reason if there are under ground base's the government would have been the one's to build them, So you bet they know,Oh could they not..

And if the poster did mean alien base's, I think someone would have seen them in the area don't you.. Beside's why would a alien need a base here on Earth, Mars would be much safer and no human's to want tax's on the land they used!

Why have an underground base on Earth when you can use the use the Moon? Place a few sensors in strategic places, and with the way the moon orbits, you can get pretty good coverage of the entire planet without wasting energy... besides, we all know the moon is hollow- and possibly artificial...

Secret Military Underground bases that are public knowledge have always been a good idea for National Security?