Stevns Klint lies about 45 minutes drive from Copenhaguen. It is a 15 km long cliff along the coastline in which it is very easy to see different layers of strates. The upper strate is a Creataceous chalk (rich in fossiles) and the lower strate is a Tertiary Period limestone.
The boundary between the Crataceous and Tertiary layer is a layer of fish clay, containing traces of great mass death (massive extinction of animals thought to be due to Earth being hit by a massive asteroïd).
Visit to Stevn Klint is like reading in the Earth History Book. And those layer can be seen by inexpecienced persons.
I drove to the village of Hojerup. The old church of that village is right on the cliff edge. Part of the churhc even collapsed into the sea in 1928. A strairway leads to the beach, where you can actually touch the different layers (and maybe find fossiles - even if I did not). Back up again, a pathway follows the cliff edge (you can actually hike along the 15 km of the cliffs). There is a small museum there.
A few minutes north is the Setns Fyr (a lighthouse) from where you can see the Oresund bridge to the north and the Mon Island in the south.
Altogether, the Stevns Klint is a nice half day trip from Copenhague, altough only with good weather confitions.