This might be "Environment" by Chester S. Geier, originally published in the May 1944 issue of Astounding, and the full text of which is available online courtesy of the Internet Archive.
Two explorers do land on a planet described as "almost a second Earth" and which had apparently once held human-like creatures:
Harlan touched ground, joined Gaynor in a tense scrutiny of the
design. A procession of strange, lithe beings was pictured in
bas-relief around the curving base of the fountain. Their forms were
essentially humanoid, possessed of two arms, two legs, and large,
well-formed head. Except for an exotic, fawnlike quality about the
graceful, parading figures, Gaynor and Harlan might have been gazing
at a depiction of garlanded, Terrestrial youths and maidens.
The planet features not quite a museum but a seemingly-abandoned city. Among the buildings are multiple abandoned spaceships, including a previous colony ship from the protagonists' planet:
The four ships which Gaynor and Harlan had found had two things in
common. Each had been built by a different humanoid people, and each
was completely deserted. Other than this, there was no basis of
comparison between them. Each was separate and distinct, unique in its
alienness. Even the Ark, long outmoded, seemed strange.
The two explorers spend time poking about the ruins, encountering technology which they don't understand. They get the idea that the whole city is a kind of primer, and start at one end to try to understand. They quickly make progress:
Instruction followed application, and in a very few days again, Gaynor
and Harlan moved on. Thus they went, from unit to unit, and always the
wall painting pointed out the way...
The machines grew larger, more intricate, ever more difficult of
solution. Each was a new test upon the growing knowledge of Gaynor and
Harlan. And each test was harder than the last, for the wall paintings
no longer pointed out the way, but merely hinted now.
As they reach the end of the city, much altered by what they have learned and learned to do, the two explorers transcend human existence and become a kind of crystalline life form that they had seen in the area when they first arrived. Encouraging this transformation is the entire point of the city. The last line is:
A perfect environment, the city. Ideal for the inquisitive humanoid.
ISFDB doesn't list a Dutch translation, and it doesn't actually turn out to be Earth, but it seemed like a possible match.