National Museum of Denmark
National museum of antiquities
"The National Museum is Denmark’s largest museum of cultural history. The museum's main domicile is a classical 18th century mansion just a stone's throw from "Strøget" at the center of Copenhagen. The National Museum is the museum for all Denmark, where you can follow the history of the Danes right down to the present day. And you can get around the world from Greenland to South America."
The Nationalmuseet is also responsible for a number of other museums.
With one of the longest histories of prehistoric archaeology in the world. Denmark's Nationalmuseet unsurprisingly contains a large amount of Mesolithic material.
Excellent website in Danish, English and German (be warned if one selects English on the home page the links to the detailed Mesolithic content disappear!).
The detailed coverage includes a number of highlight items. Good images throughout the pages include 3D interactive images of several items (eg, an amber bear).
The Mesolithic portion forms the first section of the website portion dedicated to the oldtid (roughly equivalent to prehistory but including the Viking period). This web content parallels a major portion of the actual museum.