Unfortunately, you are mixing up Liseberg with Gröna Lund, Liseberg is located in Gothemburg, Gröna Lund is located in Stockholm (and probably has the highest density of roller coasters in the world.
You ar absolutely right in that Stockholm is a very pretty city, it certainly is, and I do recommend you visiting some time.
Unfortunately, you are mixing up Liseberg with Gröna Lund, Liseberg is located in Gothemburg, Gröna Lund is located in Stockholm (and probably has the highest density of roller coasters in the world.
You ar absolutely right in that Stockholm is a very pretty city, it certainly is, and I do recommend you visiting some time.