In Bucharest we have an entire subway station tiled with marble containing countless very visible fossils [1], specifically of rudists [2]. Here are a few nice photos:

https://www.descopera.ro/wp-content/uploads/media/401/321/59...

https://www.descopera.ro/wp-content/uploads/media/401/321/59...

[1] https://en.m.wikipedia.org/wiki/Politehnica_metro_station

[2] https://en.m.wikipedia.org/wiki/Rudists