What is the correct way to say "that sign" in spanish?

This sentence stands for demonstrative adjectives. The demonstrative pronouns, such as este, ese and aquel can act as demonstrative adjectives when placed before a noun. So these adjectives demonstrate a quality about the noun they modify. Here that quality is the location in respect to the speaker or the listener. Ese indicates something more distant, that is, nouns that are further from the speaker but they can be close to the listener.

18th century i believe it is.