This is the 4760th most frequent Russian word.
заметную
Noticeable; significant; prominent.
Here, 'заметную' modifies 'башня', highlighting that the tower stands out or catches attention in its surroundings.
В парке построили заметную башню.
A noticeable tower was built in the park.
Here, 'заметную' is used as an adjective describing 'запись', indicating the importance or prominence of the entry.
Она оставила заметную запись в дневнике.
She left a noticeable entry in the diary.
In this instance, 'заметная' describes 'улыбка', referring to the visibility or distinctness of the smile.